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in  2010  with  funding  from 

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http://www.archive.org/details/moderndentistry1920head 


PREFACE  TO  THE  SECOND  EDITION 


Dentistry  up  to  the  last  ten  years  made  little  or  no  advance 
along  the  Hnes  of  Health  Conservation.  For  two  thousand 
years  dentistry  has  been  devising  collectors  of  filth  and  spreaders 
of  general  disease.  The  Roman,  who  strapped  loose  necrotic 
teeth  to  firm  teeth  with  gold  bands,  defied  the  laws  of  health  and 
cleanliness  no  more  than  many  of  our  bridge  workers  of  the 
present  day.  The  dentist  of  the  seventh  century,  in  putting 
in  gold  fillings,  to  all  intents  and  purposes  used  the  same  method 
as  that  of  the  soft-gold  worker  of  the  twentieth  century. 

Dentistry,  owing  to  the  teachings  of  Pasteur,  has  at  last 
awakened  to  its  great  responsibility.  Henceforth  no  appHance, 
however  beautiful  externally,  will  be  tolerated  unless  it  can  be 
kept  absolutely  clean,  and  no  repair  of  a  tooth  or  root  will  be 
countenanced  unless  it  conforms  to  the  standards  of  scientific 
mouth  hygiene.  FilKngs,  crowns,  and  bridges  are  no  longer 
to  be  considered  mere  objects  of  art  for  personal  adornment 
or  mechanical  trituration  of  food,  they  must  primarily  be 
hygienic. 

Through  the  elimination  of  mouth  infection,  and  of  much  con- 
sequent systemic  disease,  dentistry  must  take  a  place  in  the  fore- 
most ranks  of  preventive  medicine.  Dentists  henceforth  must 
be  trained  along  medical  Knes,  and  any  contention  that  has  existed 
in  the  past  between  the  physician  and  dentist  must  disappear 
in  a  common  endeavor  to  free  the  community  at  large  from  the 
deadly  effects  of  mouth  infection.  For  this  disease  is  now 
recognized  as  an  almost  universal  one  that  every  year  kills  its 
victims  directly  or  indirectly  by  the  hundreds  of  thousands, 
and  it  is  the  author's  hope  that  this  book  will  be  of  some  service 
in  its  cure  and  prevention. 


12  PREFACE 

The  author  wishes  to  express  his  thanks  to  Dr.  Wm.  H.  Hoedt 
for  his  valuable  co-operation  in  illustrating  this  work,  and  he 
wishes  further  to  acknowledge  his  obligation  to  Dr.  A.  P.  Hitch- 
ens  and  Dr.  Claude  P.  Brown  for  their  bacteriological  specimens 
and  their  friendly  assistance.  The  original  radiographs  from 
which  the  reproductions  of  Chapter  X  have  been  made  are  the 
masterly  work  of  Dr.  Wilhs  F.  Manges. 

Joseph  Head. 

Philadelphia,  Pa., 
January,  ig20. 


CONTENTS 


CHAPTER  I 

PAGE 

Causes  and  Effects  of  Mouth  Infection 17 

CHAPTER   II 

Prevention  of  Mouth  Infection 26 

Mouth  Cleansing 26 

Method  of  Using  Floss-silk 31 

Method  of  Brushing  the  Teeth 35 

CHAPTER  III 

A  Study  of  Tooth  Enamel  and  Saliva 43 

Enamel  Softening  and  Hardening 43 

Force  Required  in  Mastication 54 

Dentifrices  and  Mouth-washes 5^ 

Destructive  Action  of  Dentifrices 60 

CHAPTER  IV 

Treatment  of  Mouth  Infection 65 

General  Diagnosis 65 

Violet-ray  Treatment 74 

Local  Treatment 75 

Tartar  Solvent 80 

CHAPTER  V 

Vaccines  in  Treatment  of  Mouth  Infection 85 

Theory  of  Vaccination 85 

Anaphylaxis 88 

Preparation  of  Vaccines 9° 

Autogenous  and  Stock  Vaccines 91 

Obtaining  Parent  Germs  for  Vaccine 93 

Sensitized  Vaccine 98 

Vaccine  Dosage i°o 

Vaccines  and  Anemia 106 

Vaccines  and  Osteo-arthritis to6 

13 


14  CONTENTS 

CHAPTER  VI 

PAGE 

Treatment  of  Root  Canals 109 

Alveolar  Abscess 109 

Local  Anesthesia no 

Gum  Infiltration 114 

Nerve-blocking 114 

Pressure  Anesthesia 117 

Removal  of  Dental  Pulp 1 20 

Tooth  Nutrition  by  Peridental  Membrane 121 

Root  Canal  Preparation 122 

Sterilization  and  Root  Canal  Filhng. 124 

Calahan  Method 126 

Emetin 128 

Canal  Variations 128 

Bleaching 133 

Root  Amputation  and  *-Ray  Diagnosis 137 

Root  Excision 142 


CHAPTER  VII 

FiLUNGS 150 

Operative  Efficiency 150 

Old  Hammered  Filling 151 

Porcelain  Inlays 154 

Porcelain  Strength 155 

Porcelain  Inlay  Matrix 161 

Construction  of  Porcelain  Inlay 162 

Color  Selection 170 

Making  and  Baking  the  Filling 174 

Inserting  the  Inlay 176 

Gold  Inlay 179 

Plastic  Fillings 184 

Amalgam 185 

Repair  of  Broken  Roots 188 

Gutta-percha  Fillings 192 


CHAPTER  VIII 

Children's  Teeth 195 

Gum  Lancing 195 

Care  of  Children's  Teeth  and  Gums 197 

Exposed  Pulp  in  Temporary  Teeth 203 

Fractured  Teeth 204 

Orthodontia  for  the  General  Practitioner  of  Dentistry 207 

Extirpation  of  the  Frenum 239 

Impaction  of  Teeth 242 

Malnutrition 252 


CONTENTS  1$ 

CHAPTER   IX 

PACE 

Crowns 258 

Pin  Crown 260 

Amalgam  Crown  with  Porcelain  Facing 267 

Inlay  Crowns 268 

Band  Crown 272 

CHAPTER  X 

Replacing  of  Lost  Teeth 282 

The  Attached  Bridge 282 

Removable  Appliances 290 

Divergent  Abutments 292 

Double  Clasp  Bridge 298 

All-Gold  and  Porcelain  Fixture ^ 303 

CHAPTER  XI 

Experiments  Concerning  Strength,  Solubility,  and  Adhesiveness  of 

Various  Cements 3°? 

Silicious  Cements 3°7 

Phosphate  of  Zinc  Cements 309 

Tests  on  Cement  Line 31° 

Adhesion  of  Cement 320 

Cement  as  Inlay  Bond 327 

Solubihty  of  Cement  Line 327 

CHAPTER  XII 

Study  of  Roots  and  Gums  by  Means  of  x-Ray 335 

Interpretation  of  Plates 337 

Index 377 


MODERN    DENTISTRY 


CHAPTER  I 


CAUSES  AND  EFFECTS  OF  MOUTH  INFECTION 

The  term  mouth  infection  means  a  condition  where  disease- 
bearing  germs  have  estabhshed  themselves  within  the  tissues 
of  the  mouth,  the  vital  resisting  force  of  these  tissues  having 
been  temporarily  or  permanently  lowered  by  systemic  disease  or 
some  depressing  local  condition. 

Mouth  infection  is  generally  associated  with  red,  swollen 
gums,  with  or  without  the  presence  of  exuding  pus,  and  teeth 
sensitive  to  heat,  cold,  or  pressure.  In  ninety-nine  cases  out  of 
a  hundred  the  teeth  and  the  gums  are  the  primary  seat  of  the 
disease,  but  occasionally  it  is  confined  to  the  cheeks,  palate,  or 
lips  in  the  form  of  superficial  self-healing  ulcers,  syphilitic  sores, 
or  slowly  progressive  areas  of  inflammation  that  sooner  or  later 
mean  cancer.  Any  persistent  fissure  or  inflammatory  hardening 
of  the  cheek  or  lips  has  so  long  been  known  to  threaten  pro- 
longed sickness  and  death  that  the  incipient  mahgnant  forms  of 
mouth  infection  generally  receive  prompt  attention  and  treatment. 
All  abnormal  growths  in  the  mouth  may  be  malignant,  and  on 
their  first  appearance  should  be  cut  out  for  examination  and 
diagnosis. 

This  book,  however,  will  deal  with  infections  of  the  gums  and 
teeth,  infections  that  have  been  complacently  endured  in  chronic 
form  ever  since  man  came  upon  this  globe.  For  just  as  the  ticks 
and  fleas  of  India  can  convey  the  death-dealing  plague  from  one 
person  to  another,  so  these  patiently  borne  gum  and  tooth  in- 
fections are  now  known  to  originate  a  long  list  of  fatal  diseases, 

2  17 


1 8  MODEEN  DENTISTRY 

among  which  are  found  valvular  heart  disease,  anemia,  arthritis 
deformans,  rheumatism,  and  nervous  derangements  without  end. 

No  doubt  the  first  of  the  cave-dwellers  who  strove  to  free 
himself  from  vermin  was  called  a  finicky  dandy.  No  doubt  he 
was  warned  by  the  old  men  of  the  tribe  that  he  was  endangering 
his  health  and  even  Kfe,  and  that  if  he  made  his  body  unaccus- 
tomed to  vermin,  when  he  did  become  infested,  the  tissues  would 
have  lost  their  defensive  power  against  them.  In  the  same  way 
we  have  modern  cave-men  among  us  who  sneer  at  excessive 
mouth  cleansing  as  an  absurd  fad,  some  even  claiming  that 
there  are  germs  in  the  mouth  that  have  a  benign  influence  for 
health.  In  answer  to  these  cave-men,  whose  real  reason  is 
laziness,  not  science,  it  must  be  pointed  out  that  a  germ,  like  a 
man,  cannot  escape  being  judged  by  the  company  it  keeps, 
and  that  when  the  machine-guns  are  leveled  against  a  mob  the 
innocent  passer-by  performs  a  patriotic  duty  in  accepting 
death  that  the  streets  may  be  cleared  and  law  and  order  re- 
stored. 

Therefore,  in  spite  of  the  fact  that  some  of  the  numerous 
germs  that  lurk  within  the  mouth  may  have  beneficial  possi- 
bihties,  this  vague  chance  must  give  way  before  the  certain 
knowledge  that  the  germs  of  pneumonia,  influenza,  diphtheria, 
and  catarrh,  with  a  host  of  other  disease-forming  germs,  are 
practically  always  present  in  every  mouth.  These  germs  in  a 
healthy  mouth  may  be  harmless,  but  the  moment  they  succeed 
in  obtaining  entrance  to  an  area  of  weakened  or  inflamed  tissue 
they  shortly  become  forerunners  of  their  respective  diseases, 
both  local  and  systemic.  Healthy  blood,  in  conjunction  with 
healthy  tissue-cells,  is  fully  capable  of  restraining  the  growth  of  a 
limited  number  of  disease  germs.  Even  the  dreaded  tubercle 
bacillus  can  be  controlled  and  destroyed  by  healthy  tissues  if  the 
germs  appear  only  in  very  Kmited  numbers.  Therefore,  it  is  of 
the  utmost  importance  that  the  blood  and  the  tissues  shall  be 
kept  at  their  normal  power  to  control  these  germs  that  are  ever- 
present  in  the  mouth;  and  if  these  germs  do  gain  an  entrance  to 
the  tissues,  to  destroy  them  before  they  can  multiply  sufiiciently 
to  cause  disease. 


CAUSES   AND   EFFECTS   OF  MOUTH   INFECTION  1 9 

General  Causes  of  Mouth  Infection.^ — With  such  a  picture 
of  bacterial  invasion  before  our  eyes,  we  are  confronted  with  a 
problem  that  for  centuries  interested  the  philosophers  as  to 
which  comes  first,  the  egg  or  the  owl.  That  there  are  two  causes 
of  bacterial  invasion — the  systemic  and  the  local — is  unques- 
tionable, but  in  any  particular  case  it  is  usually  difficult  to  say 
whether  the  original  multipHcation  of  an  infecting  bacterium 
first  arose  from  deficient  bactericidal  power  of  the  blood,  or 
whether  a  local  bruising  or  infiltration  of  the  tissues  reduced 
their  defensive  power  against  the  germs  to  a  degree  where  even 
healthy  blood  might  not  be  able  to  resist  the  bacterial  growth 
and  consequent  onset.  However  this  may  be,  there  is  no  doubt 
that  progressive  weakness  in  either  systemic  or  local  resistance 
will  infallibly  result  in  a  final  depression  that  is  characteristic 
of  both. 

For  instance,  the  constant  drinking  of  water  or  beer  containing 
lead  will  cause  a  systemic  depression  that,  in  addition  to  a  palsy 
of  the  wrists  and  intestinal  derangement,  also  causes  the  blue 
line  of  gum  infection  around  the  teeth  that  is  diagnostic  of 
chronic  lead-poisoning.  In  the  same  way  the  constant  use  of 
calomel  as  an  internal  medicine  wiH  cause  such  a  destructive  in- 
flammation of  the  gums  around  the  teeth  that  the  latter  will 
loosen  and  even  drop  out.  In  each  instance  the  primary  cause 
of  the  bacterial  invasion  of  the  gums  is  systemic,  and  the  ever- 
present  micro-organisms  first  obtain  their  lodgment  in  a  mass 
sufficient  to  defy  the  contending  tissue-cells  solely  because  of  a 
general  depression  of  the  body  at  large.  If,  however,  after  the 
abscesses  around  the  teeth  are  fully  established  in  an  area  of  dead 
and  dying  tissue,  the  lead  or  calomel  is  stopped  and  that  which  has 
been  taken  is  elimmated  by  the  mtestines  and  kidneys,  the  ab- 
scesses around  the  teeth  may  nevertheless  continue  because  the 
tissue-ceUs  around  them  lack  their  original  germicidal  power. 
And  even  if  the  blood  generally  should  regain  its  normal  germi- 
cidal power,  it  would  be  unable  to  effectively  reach  and  combat 
the  invading  masses  of  infection  that  are  now  securely  fortified 
behind  the  dead  or  weakened  tissue-cells;  and  the  invading 
germs  will  continue  to  feed,  and  just  as  surely  advance  their 


20  MODERN  DENTISTRY 

devastations  wherever  the  tissue-cells  show  further  weakened 
resistance. 

As  an  illustration  of  a  purely  local  source  of  mouth  infection, 
let  us  take,  for  example,  a  tooth  that  starts  to  decay  through  the 
impaction  of  food  in  an  improperly  developed  fissure  of  the 
enamel.  The  food  ferments  and  acid  is  formed  that  dissolves 
and  softens  the  tooth  substance  so  that  bacteria  can  penetrate 
along  the  dentin  filaments  to  the  nerve,  or  pulp,  as  it  is  called. 
The  blood  in  the  pulp  throws  out  a  protecting  layer  of  tooth  bone 
between  it  and  the  infection.  Finally,  the  pulp  loses  the  power 
of  producing  immunizing  substances  with  which  it  can  combat 
the  disease,  and  accepts  the  infecting  germs,  which  it  deposits 
in  the  gum  around  the  tip  of  the  root.  An  infected  living  pulp 
may  cause  abscesses  that  are  self-perpetuating  and  that  will 
infect  the  system  at  large.  This  will  finally  lower  the  body 
resistance,  and  so  the  infection  that  started  in  a  purely  local 
manner  may  end  in  general  disease. 

As  above  stated,  the  systemic  cause  of  mouth  infection 
may  not  only  be  tuberculosis,  malaria,  rheumatism,  typhoid 
fever,  or  any  of  the  major  diseases  common  to  man,  but  it  may 
be  merely  a  bad  cold  or  a  passing  attack  of  grip,  which  by  lower- 
ing the  vital  resistance  will  allow  the  self-perpetuating  abscesses 
of  mouth  infection  to  be  formed.  And  it  is  equally  true  that  a 
mouth  infection  caused  by  a  badly  fitting  crown  or  a  filth-col- 
lecting bridge  may  be  the  primary  cause  of  systemic  depression 
that  will  allow  the  body  to  become  a  prey  to  any  of  the  systemic 
diseases  or  infections  just  mentioned,  when  without  such  local 
infections  the  body  might  have  had  sufficient  vital  resistance  to 
repulse  the  onset  of  systemic  disease  and  maintain  a  normal  con- 
dition of  health. 

The  obvious  cure  for  mouth  infection  of  a  purely  systemic 
origin  is  the  removal  of  the  cause  of  the  systemic  depression, 
but  as  this  deals  with  practically  the  whole  realm  of  general 
medicine  this  phase  will  not  be  discussed  here.  The  obvious 
cure  for  mouth  infections  of  local  origin  is  also  the  complete 
removal  of  the  cause,  and  with  that  thought  in  our  minds  the 
various  local  causes  of  mouth  infection  will  now  be  considered. 


CAUSES    AND    EFFECTS    OF    MOUTH   INFECTION  21 

Local  Causes  of  Mouth  Infection.— The  most  fruitful  local 
causes  of  mouth  infection  are  improper  mastication  of  food 
and  inefficient  daily  cleansing  of  the  mouth.  Nine-tenths,  if 
not  ninety-nine-hundredths  of  the  local  mouth  infections  can  be 
traced  fundamentally  to  these  two  great  causes.  All  the  other 
causes  follow  after  these  almost  as  a  matter  of  course,  such  as 
decay  of  the  teeth,  and  infection  and  death  of  the  dental  pulps 
or  "nerves."  Next  follows  impaction  of  food  between  the  teeth, 
with  the  consequent  destruction  of  the  gum  that  protects  the  roots. 
The  bone  between  the  teeth,  being  exposed,  becomes  infected 
and  absorbed,  leaving  a  hole  or  pocket  that  cannot  be  properly 
cleansed;  and  this  pocket,  therefore,  becomes  a  permanent  and 
ever-spreading  focus  of  disease,  so  that  the  membrane  supporting 
what  may  be  a  perfectly  healthy  tooth  gradually  breaks  down 
more  and  more,  until  the  nerve  trunk  and  blood-vessels  at  the 
root  tips  become  infected  and  finally  destroyed.  This  causes 
the  death  of  the  pulp  in  a  tooth  that  may  not  show  external  signs 
of  decay.  Thus  another  depot  of  infection  is  formed  that  can 
only  be  eliminated  by  boring  into  the  tooth,  removing  the  pulp, 
and  sterilizing  and  filling  the  root  canals. 

The  fact  that  a  tooth  without  decay,  containing  a  Hve  pulp, 
or  nerve,  may  be  a  source  of  infection  makes  the  diagnosis  of 
whether  there  is  mouth  infection  a  matter  of  great  nicety.  The 
fact  that  a  tooth  with  poison-spreading  chronic  abscesses  may 
be  perfectly  normal  in  appearance,  sensation,  and  function 
still  further  adds  to  the  difficulty.  This  matter  of  diagnosis 
will  be  minutely  discussed  later  on,  but  its  difficulty  makes 
the  discovery  of  masked  mouth  infection  by  the  general  prac- 
titioner a  matter  of  great  uncertainty  or  even  impossibility, 
unless  the  physician  has  had  the  necessary  diagnostic  instruc- 
tion in  this  most  important  subject.  Only  too  often  do 
physicians  make  careful  general  systemic  examinations,  but 
take  merely  a  casual  look  at  the  teeth  and  gravely  pronounce, 
"no  mouth  infection."  Tuberculosis  of  the  lungs  is  easily  recog- 
nized in  its  advanced  stages,  but  it  is  cured  in  exact  ratio  to  its 
early  diagnosis,  and  the  spread  of  systemic  disease  by  mouth 
infection  is  in  the  same  manner  prevented  by  its  early  recog- 


22  MODERN  DENTISTRY 

nition.  As  a  matter  of  fact,  the  general  practitioner  only  recog- 
nizes mouth  infection  in  its  advanced  stage,  when  many  of  its 
systemic  sequelae  are  already  firmly  intrenched. 

The  packing  of  food  between  the  teeth,  whether  there  is 
decay  or  not,  should  always  be  considered  a  forerunner  of  mouth 
infection  with  the  probable  consequent  loss  of  the  teeth.  The 
packing  of  food  between  the  teeth,  as  above  stated,  is  not  always 
associated  with  decay,  but  may  be  due  to  a  gum  infection  alone 
which  weakens  the  supporting  membrane  about  the  teeth.  These 
teeth  spring  apart  under  the  force  of  mastication  with  resultant 
bruising  of  the  gum  and  ultimate  pockets  of  infection.  We  also 
have  pockets  of  infection  between  the  teeth  that  owe  their 
origin  to  the  projecting  edges  of  fillings  and  ill-fitting  crowns 
that  during  mastication  constantly  drive  the  infection  into  the 
helpless  gum.  Furthermore,  infection  is  caused  by  uncleansable 
bridges,  frequently  inserted  over  gums  already  infected,  and  by 
plates  that  are  made  primarily  to  aid  mastication,  while  in  only 
too  many  instances  they  hasten  the  destruction  of  the  teeth  that 
they  are  designed  to  supplement. 

These  facts  are  so  obvious  that  a  glance  in  the  average  mouth 
will  show  instances  of  such  infection  again  and  again.  And  it  is 
not  as  though  such  crowns  and  bridges  were  considered  anti- 
quated. They  are  approved  and  recommended  in  the  every-day 
curriculum  of  many  of  our  leading  dental  colleges  by  faculties 
that  complacently  look  on  their  work  as  largely  a  question  of 
mechanics,  while  their  mechanical  teachings  and  methods 
continue  to  spread  infection  and  disease. 

Dentistry  is  rapidly  coming  to  be  one  of  the  foremost 
branches  of  preventive  medicine,  and  in  a  short  while  no  den- 
tist will  be  allowed  to  practice  unless  he  also  has  general  medical 
training.  Those  who  do  not  recognize  this  vital  fact  and  con- 
tinue to  practice  methods  that  create  and  perpetuate  mouth 
infection  will  soon  be  relegated  to  obHvion,  while  a  new  and  more 
scientific  class  of  men  will  take  their  places. 

Many  interesting  experiments  have  been  made  with  the  Strep- 
tococcus viridans,  a  germ  which  is  frequently  found  in  the  pockets 
of  mouth  infection.     Injected  into  the  ear  of  a  rabbit  whose 


CAUSES   AND   EFFECTS   OF  MOUTH   IISTFECTION  23 

heart  had  been  artificially  strained,  the  Streptococcus  viridans, 
upon  autopsy,  has  been  recovered  from  the  inflamed  valves  of 
the  heart.  A  macroscopic  study  of  such  animal  postmortem 
heart  specimens  has  sometimes  shown  a  calcareous  deposit  that 
is  not  dissimilar  to  the  inflammatory  calcareous  deposits  found 
on  the  roots  of  teeth.  This  is  particularly  interesting  as  there  is 
unquestionably  a  relation  between  tooth  tartar  and  general 
systemic  depression  due  to  mouth  infection,  the  mouth  tartar 
decreasing  perceptibly  as  the  immunizing  bodies  of  the  blood 
become  more  and  more  in  control  of  the  situation. 

Effects  of  Mouth  Infection. — ^The  following  case  is  an  inter- 
esting example  of  secondary  infection  from  a  pyorrhea  pocket: 
A  young  physician  declared  that  he  believed  the  condition  of  his 
teeth  was  causing  a  swelhng  of  his  tonsil.  A  casual  look  in  the 
mouth  gave  the  impression  of  gums  that  were  perfectly  healthy, 
but  an  exploration  between  the  upper  second  and  third  molars 
revealed  a  pocket  that  almost  exposed,  the  tips  of  the  adjacent 
roots  of  both  teeth.  An  appHcation  was  made  of  ammonium 
bifluorid.  The  patient  returned  in  a  week  and  the  tonsil  that  had 
been  greatly  swollen  had  practically  returned  to  its  normal  size. 
And  from  then  on  during  the  treatment  it  was  clearly  demon- 
strated that  as  the  pocket  showed  signs  of  reinfection  the  tonsil 
would  swell,  and  that  when  the  pocket  finally  yielded  to  medi- 
cation the  tonsil  returned  to  its  normal  state.  This  case  shows  an 
intimate  relation  between  the  tonsils  and  gum  infection,  appar- 
ently indicating  that  where  they  exist  in  common  all  the  disease 
previously  attributed  to  the  tonsils  alone  may  equally  as  well  be 
attributed  to  gum  infection. 

Another  case  was  that  of  chronic  infection  of  the  internal 
ear.  The  physician  was  unable  to  find  any  local  cause,  and  sug- 
gested that  the  trouble  arose  from  reflex  dental  infection.  The 
removal  of  an  infected  Hving  pulp  in  the  upper  second  molar 
caused  the  ear  to  clear  up  immediately. 

A  patient  had  a  chronic  abscess  in  an  upper  molar  that  was 
associated  with  pronounced  swelling  of  the  submaxillary  salivary 
gland  on  the  same  side.  When  the  infection  in  the  upper  jaw 
was  treated  the  gland  in  the  lower  jaw  returned  to  its  normal 


24  MODERN  DENTISTRY 

size;  but  when  the  infection  returned,  as  it  did  several  times 
because  the  patient  would  not  take  his  treatments  with  proper 
regularity,  the  submaxillary  gland  would  invariably  become 
swollen  again.  When  the  tooth  became  cured  of  its  infection, 
the  gland  regained  its  normal  condition  permanently. 

These  cases  are  presented  to  show  the  intimate  connection 
between  the  gums  and  tonsils,  the  gums  and  the  ear,  and  the 
gums  and  the  salivary  glands.  A  more  extraordinary  case  was  one 
where  the  infection  of  a  lower  second  molar  caused  a  partial  loss 
of  sight  in  the  eye  on  the  same  side  of  the  face.  In  the  course 
of  examining  the  teeth  of  a  young  woman  the  author  noticed  a 
submaxillary  swelhng.  This  was  traced  to  the  second  molar, 
which,  on  being  opened,  revealed  an  infected  pulp.  This  pulp 
was  removed  and  the  tooth  treated  antiseptically  for  a  series  of 
treatments,  during  which  the  submaxillary  gland  decreased  in 
size  as  the  antiseptics  were  appHed.  After  the  first  treatment 
the  patient  said  that  her  sight  was  much  improved.  Later  on, 
with  each  treatment,  she  spoke  of  the  continued  improvement 
of  her  eye,  and  finally,  when  the  tooth  was  cured,  she  said  as  she 
left,  "I  had  to  give  up  my  art  studies  on  account  of  that  eye, 
but  I  am  now  going  to  return  to  them."  Later  she  went  to  her 
oculist,  who  six  months  before  had  found  her  sight  in  that  eye 
more  than  half  gone,  and  he  corroborated  her  statements  by  an 
examination,  and  found  that  the  chronic  inflammation  had  en- 
tirely disappeared. 

There  are  other  cases  where  the  connection  between  mouth 
infection  and  general  arthritic  conditions  is  clearly  established 
by  the  fact  that  when  the  mouth  infection  was  remedied  the  gen- 
eral diseases  either  cleared  up  or  were  greatly  improved. 

This  chapter  will  close  with  a  most  interesting  case  of  spinal 
irritation  connected  with  mouth  infection.  A  young  married 
woman,  thirty  years  of  age,  came  to  the  author  for  treatment. 
About  five  years  previously  she  had  had  an  automobile  accident 
by  which  the  base  of  her  spine  had  been  so  injured  that  it  was 
impossible  for  her  to  remain  in  a  sitting  posture  for  more  than 
half  an  hour  at  a  time.  Two  or  three  of  her  teeth  showed  so 
marked   a   sensibility   to   heat   and    cold   that   the    pulps,    or 


CAUSES  AND  EFFECTS  OF  MOUTH  INFECTION        2$ 

nerves,  had  to  be  removed.  The  teeth  also  showed  irritation  at 
the  root  tips  characteristic  of  spinal  irritation,  which  made  it 
practically  impossible  to  fill  the  nerve  canals.  Any  such  attempt 
was  accompanied  by  such  pain  and  signs  of  suppuration  that  no 
progress  of  any  sort  was  made  for  over  a  month.  Finally,  a 
sterilized  piano-wire  drill  was  passed  down  a  sterilized  root  canal 
and  plunged  into  the  sensitive  area  at  the  root  tip;  a  material 
was  obtained  which  yielded  only  a  single  type  of  streptococcus. 
From  this  an  autogenous  vaccine  was  made  and  the  patient 
was  treated  with  the  vaccine  about  eight  times,  once  each  week. 
After  the  fourth  treatment  it  was  quite  possible  to  fill  the  canals 
of  air  the  teeth  where  the  nerves  had  been  removed.  After  the 
eighth  treatment  she  was  able  to  sit  up,  and  since  that  time  has 
had  no  further  trouble  with  her  spine.  Evidently  the  infection 
of  the  teeth  and  the  infection  of  the  spine  came  from  the  same 
germ,  and  the  systemic  cure  of  the  gums  at  the  same  time  cured 
the  spine. 

Medical  literature  is  full  of  startling  cases  where  the  intimate 
interdependence  of  mouth  infection  and  grave  general  systemic 
disease  is  clearly  indicated,  but  these  just  mentioned  are  of  in- 
terest as  they  have  come  under  the  author's  personal  experience. 

However,  this  chapter  cannot  be  brought  to  a  close  without 
emphasizing  the  fact  that  leukoplakia  (a  white  semi-malignant 
growth),  tuberculous  abscesses,  Vincent's  angina,  a  rapidly  pro- 
gressive infection,  and  cancer  of  the  mouth  are  all  so  closely 
associated  with  a  history  of  tooth  and  gum  infection  as  to  make  it 
a  matter  for  serious  consideration  whether  any  of  these  dreaded 
diseases  may  not  be  a  direct  result  of  the  ordinarily  neglected 
every-day  diseases  of  the  teeth  and  gums. 

The  normal  age  of  man  is  now  the  biblical  threescore  and  ten, 
but  when  the  simple  rules  for  preventing  mouth  infection  are 
generally  known  and  enforced  as  a  matter  of  public  poHcy,  one 
cannot  foretell  how  much  human  Kfe  will  be  extended,  but  that 
it  will  be  greatly  extended  there  is  every  reason  to  believe. 


CHAPTER  II 

PREVENTION  OF  MOUTH  INFECTION 

Mouth  Cleansing. — The  most  important  treatment  in  the 
prevention  of  mouth  infection  is  the  mechanical  removal  of  the 
masses  of  disease  germs  from  the  teeth  and  gums.  After  this  has 
been  done  a  mild  antiseptic  wash,  such  as  a  i  per  cent,  solution 
of  peroxid  of  hydrogen,  held  in  the  mouth  for  a  minute  or  two, 
will  be  able  to  inhibit  the  growth  of  the  remaining  bacterial 
film  until  it  is  time  to  cleanse  the  mouth  mechanically  again. 
For  germs  of  disease  are  dangerous  not  only  as  germs,  but  they 
are  dangerous  in  direct  proportion  to  their  number  and  the 
length  of  time  they  are  permitted  to  make  their  attack  on  the 
tissues.  The  immunizing  bodies  of  normal  blood  can  readily  re- 
sist a  few  germs  of  disease  for  an  indefinite  time,  but  when  the  un- 
disturbed germs  are  allowed  to  grow  indefinitely  the  resistance 
of  the  tissue-cells  is  overthrown  through  a  continued,  ever-in- 
creasing efficiency  of  attack.  Therefore  it  is  evident  that  the 
fundamental  remedy  is  to  keep  the  ever-present  disease  germs 
reduced  to  a  film  so  thin  that  the  resistance  of  the  blood  in  the 
gums  will  always  be  able  to  cope  with  any  depressing  influence 
that  such  a  small  bacterial  mass  can  develop.  It  is  also  essential 
to  keep  the  bacterial  masses  on  the  teeth  so  thin  that  they  cannot 
secrete  enough  acid  to  effect  a  softening  of  the  enamel  through 
which  the  germs  may  find  an  entrance  into  the  interior  of  the 
tooth  substance. 

The  three  acknowledged  means  of  removing  and  inhibiting 
the  growth  of  the  bacterial  masses  are:  (i)  the  floss-silk;  (2) 
the  tooth-brush;  (3)  the  mild  antiseptic  wash.  The  scientific  use 
of  the  floss-silk  is  absolutely  essential  in  the  daily  cleansing  of 
the  mouth,  and  yet  the  reasons  underlying  its  scientific  use  are 
not  generally  understood.    It  is,  of  course,  useful  in  removing 

26 


PREVENTION   OF   MOUTH  INFECTION  27 

particles  of  food  that  may  act  as  culture-media  for  the  growth 
of  disease  germs,  but  the  greatest  function  of  floss-silk  is  to  remove 
the  mass  of  germs  themselves  that  would  otherwise  day  by  day, 
week  by  week,  and  month  by  month  steadily  collect  between 
the  teeth.  There  is  no  other  means  than  the  floss-silk  for  effec- 
tively removing  these  masses  from  between  the  teeth. 

Dentistry  has  recommended  pitifully  inadequate  movements 
of  the  tooth-brush  for  cleansing  between  the  teeth,  when  a  single 
glance  in  the  mouth  immediately  after  the  teeth  have  received 
such  a  brushing  will  show  that  the  tooth-brush  does  not  and 
cannot  cleanse  between  the  teeth.  In  teaching  such  misleading 
methods  of  tooth  cleansing  dentistry  has  been  perpetuating 
the  very  conditions  it  professes  to  obviate.  As  before  stated, 
the  only  instrument  capable  of  cleansing  the  spaces  between 
teeth  is  floss-silk,  and  this  should  be  swept  over  each  approxi- 
mating surface  of  the  teeth  at  least  once  a  day.  This  will  break 
up  and  remove  the  bacterial  masses  that  would  otherwise  coUect 
and  remain  year  in  and  year  out.  It  is  because  the  tooth-brush 
erroneously  is  supposed  to  remove  such  bacterial  deposits  that 
tooth  decay  nine  times  out  of  ten  starts  between  the  teeth;  and 
almost  invariably  pyorrhea  alveolaris  (Riggs'  disease)  or  gum 
infection  starts  between  the  teeth  as  soon  as  the  gum  has  receded 
sufficiently  to  make  an  interdental  space.  Because  floss-silk 
is  not  properly  used,  and  the  masses  of  bacteria  remain  undis- 
turbed, mouth  infection  starts  between  the  ages  of  five  and  ten, 
and  eventually  reveals  at  the  age  of  forty  or  fifty  its  insidious 
toll  of  general  disease.  Almost  all,  if  not  entirely  aU,  of  these 
dreadful  sequelae  can  be  avoided  if  at  the  age  of  five  the  child 
is  taught  the  use  of  floss-silk,  and  is  taught  to  cleanse  between 
the  teeth  not  for  the  sake  of  being  clean,  but  for  the  sake  of 
growing  up  strong  and  healthy.  No  child  wishes  to  take  the 
trouble  to  be  clean,  but  every  child  wishes  to  grow  up  strong 
and  weU.  Every  normal  child  wiU  labor  and  strive  to  improve 
his  body  for  the  sake  of  athletics,  and  if  he  knows  that  the 
use  of  floss-silk  is  Just  as  necessary  as  arduous  exercise,  there 
is  no  question  but  that  floss-silk  wiU  be  used,  and  used  effec- 
tively. 


28  MODERN   DENTISTRY 

Let  US  now  consider  the  use  of  the  tooth-brush  as  a  means  of 
removing  the  bacterial  masses  from  the  exposed  surfaces  of  the 
teeth  and  the  gums.  Just  as  those  who  never  use  floss-silk  never 
cleanse  between  the  teeth,  so  do  the  majority  of  those  who  brush 
the  teeth  never  really  cleanse  them.  The  cleansing  action  of  a 
tooth-brush  can  only  lie  in  bristle  friction,  and  most  well-meaning 
people  either  use  strokes  of  the  brush  that  never  get  beyond  a 
pivoting  of  the  long  bristles,  or  they  use  brushes  so  large  that 
there  is  neither  room  to  move  them  nor  to  effectively  place  them 
against  the  back  teeth.  With  all  the  talk  that  there  has  been 
about  tooth-brushing  since  Adam  delved  and  Eve  span,  the 
wisdom-tooth  has  been  as  badly  treated  as  the  nearsighted  child 
of  fifty  years  ago  who  was  relegated  to  the  dunce  cap  because 
he  could  not  see  the  letters  of  the  book  that  he  was  blamed  for 
not  understanding.  The  wisdom-tooth  enamel  is  in  structure  just 
as  sound  as  that  of  any  other  tooth,  and  it  has  its  bad  name 
simply  because  it  is  never  cleansed.  Because  the  back  molars 
are  badly  cleansed  they  are  usually  the  first  to  become  infected 
and  loosen.  The  back  molars  are  nearest  to  the  tonsils  and, 
being  uncleansed,  they  are  therefore  particularly  dangerous 
as  spreaders  of  disease. 

The  great  test  of  a  tooth-brushing  method  is,  does  it  cleanse 
where  it  is  designed  to  cleanse?  In  plain  words,  the  way  to  brush 
the  teeth  and  gums  is  to  brush  them.  Obviously,  too  large  a 
brush  is  useless.  To  use  a  2-inch  brush  with  bristles  |-inch  long, 
where  there  is  only  2|  inches  for  free  action,  means  that  there  will 
be  practically  no  bristle  friction,  which  is  what  occurs  in  most 
mouths  during  the  process  of  brushing  the  teeth.  In  the  mouth 
the  free  space  in  any  given  Kne  where  a  tooth-brush  can  operate 
is  seldom  over  2|  inches.  The  usual  brush,  being  about  2  inches 
long,  generally  reduces .  the  possible  movement  of  the  brush  to 
about  I  inch,  and  this  \  inch  is  entirely  taken  up  by  the  spring 
and  pivoting  of  the  bristles,  so  that  with  any  such  attempt  at 
brushing  there  is  very  little  bristle  friction  at  all.  Therefore  we 
should  avoid  the  use  of  the  ordinary  large  tooth-brush  and  use 
a  narrow  bristle  brush  not  over  i|  inches  long,  with  bristles  not 
over  I  inch  in  length.    This  will  allow  sufficient  room  for  genuine 


PREVENTION   OF   MOUTH   INFECTION 


29 


motion  of  the  brush  in  the  mouth ;  and  if  the  bristles  are  too  stiff 
at  first,  the  brush  should  be  placed  in  hot  water  for  a  minute 
before  using,  until  the  gums  become  accustomed  to  their  action. 
Healthy  gums  can  bear  the  same  scrubbing  as  the  flesh  around 
the  finger-nails,  and  with  the  same  benefit.  In  fact,  the  exposed 
surfaces  of  unhealthy  inflamed  gums,  when  given  a  vigorous 
scrubbing  with  a  stiff  brush  twice  a  day,  in  the  course  of  a  week 
or  ten  days  will  become  firm  and  healthy;  and  no  other  single 
treatment,  to  the  author's  knowledge,  will  accomplish  the  same 
result.  This  generally  unknown  fact  was  utihzed  some  years 
ago  by  a  certain  charlatan  who  was  trying  to  sell  his  tooth-paste. 
He  forced  his  way  into  the  office  and  immediately  began,  ''Doc- 
tor, this  tooth-paste  is  most  useful  for  the  cure  of  the  small  canker 
sores  that  so  often  come  on  the  cheek  and  gums.  All  you  have 
to  do  is  to  put  a  Httle  of  this  paste  on  the  tooth-brush  and  brush 
it  thoroughly  into  them."  "But,"  I  interposed,  "won't  the  sores 
get  well  if  they  are  brushed  with  the  tooth-brush  and  water?" 
"Why,  yes,"  he  replied,  with  a  sickly  smile,  "but  that  is  not 
usually  known." 

The  brushing  of  the  gums,  as  before  stated,  is  of  prime  impor- 
tance, but  the  intense  pain  occasioned  by  the  first  week's  work 
is  as  severe  as  the  pains  in  the  back  of  an  athlete  when  he  first 
starts  to  get  himself  into  condition.  The  trainer  tells  the  athlete 
to  go  on  with  his  work  and  that  it  will  be  all  right,  and  in  the 
same  way  tb.e  poor  patient,  though  he  fears  that  he  is  injuring  his 
gums  when  he  uses  the  brush  vigorously,  must  be  encouraged 
by  his  dentist  to  continue,  with  the  assurance  that  the  pain  in 
his  gums  will  soon  disappear.  The  author  once  showed  a  young 
lawyer  how  to  brush  his  teeth  and  gums.  He  went  away  and  the 
next  day  the  author  received  a  letter  from  him  threatening  suit 
for  having  ruined  his  face.  Amusing  as  this  incident  is,  it  has  a 
very  serious  bearing.  The  gums  to  be  healthy  must  be  scrubbed 
so  as  to  remove  the  bacterial  masses  and  also  the  dead  epithelial 
scale,  which  will  act  as  a  bacterial  food.  Scrubbing  infected 
gums  cannot  result  at  first  in  anything  but  further  infection  that 
may,  and  frequently  does,  cause  a  slight  fever,  however,  the 
bacteria  cannot  be  removed  and  the  gums  will  not  heal  unless 


30  MODERN  DENTISTRY 

this  severe  ordeal  is  endured.  The  systemic  reactions  caused  at 
times  by  brushing  infected  gums  must  be  explained  as  a  process 
of  auto-inoculation,  for  under  no  other  supposition  is  it  possible 
to  explain  why,  under  the  newly  inaugurated  thorough  brushing 
day  by  day,  the  gums  should  continue  to  be  sore  and  inflamed, 
and  then  suddenly,  between  the  seventh  and  tenth  days,  become 
healthy,  hard,  and  firm,  thereafter  standing  with  complacency 
any  amount  of  brushing. 

In  a  minor  degree  the  same  phase  is  noted  when  the  floss-silk 
is  first  used  on  infected  gums.    The  gums  at  first  naturally  bleed 


Fig.  I. — Preliminary  position  of  the  dental  silk.     Note  that  it  is  attached  solely 

to  the  little  fingers. 

and  become  further  infected  from  the  use  of  a  string  that  drives 
in  the  infecting  organism.  This  soreness  has  been  used  as  an 
argument  against  the  use  of  floss-silk,  but  it  is  not  a  just  argu- 
ment, as  a  few  days'  perseverance  will  invariably  show.  The 
persevering  scientific  use  of  floss-silk  will  always  be  followed  by 
improvement,  and,  if  the  infection  has  not  proceeded  too  far, 
by  a  complete  disappearance  of  the  infection  between  the  teeth. 
If  the  patient  was  told  that  he  must  go  through  a  week  or  ten 
days  of  discomfort  to  avoid  gout,  rheumatism,  valvular  heart 


PREVENTION  OF   MOUTH   INFECTION  3 1 

disease,  or  ulcer  of  the  stomach,  how  readily  and  gladly  would 
he  do  it,  how  cheap  would  he  consider  the  price!    But  since  he 


Fig.  2. — Method  of  holding  the  dental  silk  while  cleansing  the  upper  teeth. 

considers  it  a  question  of  mere  cleanHness,  this  ordeal  is  very 
naturally  avoided  and  these  diseases  all  become  possibilities. 


Fig.  3. — Method  of  holding  the  dental  silk  for  cleansing  the  lower  teeth. 

Method  of  Using  Floss-silk. — Careful  floss-silking  is  not 
the  simple  procedure  it  is  supposed  to  be.  Like  tooth-brushing, 
there  is  only  one  way  to  do  it  properly  and  a  hundred  ways  to  do 
it  improperly.     The  floss-silk  must  scrape  the  sticky  bacterial 


32  MODERN  DENTISTRY 

masses  from  the  sides  of  the  teeth  and  the  intervening  gum. 
Many  instruments  have  been  devised  to  hold  the  silk,  but  none 
can  equal  the  fingers  themselves  for  doing  this  most  important 
act.  The  proper  method  of  using  floss-silk  is  as  follows:  A  gen- 
erous piece  of  floss-silk  should  be  taken  and  wrapped  around 
the  little  fingers  of  both  hands  so  that  there  will  not  be  more 
than  ^  inch  of  free  silk  between  the  two  hands  (Fig.  i).  The 
thumb  and  forefinger  are  used  for  cleansing  the  upper  teeth 
(Fig.  2),  the  two  forefingers  for  cleansing  the  lower  teeth  (Fig. 
3).  There  should  not  be  a  greater  length  of  free  silk.  For  in- 
stead of  cleaning  the  bacteria  off  the  teeth  too  great  a  length 
of  free  silk  will  bend  and  pivot  like  the  bristles  of  the  brush, 
which  are  too  long.  The  tense  span  of  silk  should  go  with  a 
sliding  motion  up  one  side  of  the  interdental  space,  care  being 


A  A 

Fig.  4. — Triangle  A-B-C  shows  correct  lines  dental  floss  should  travel  in  cleans- 
ing each  interdental  space. 

taken  to  include  the  curve  of  the  tooth  on  that  side,  up  well 
under  the  frenum  of  the  gum,  then  roughly  across  the  gum  and  up 
into  the  opposite  frenum,  and  then  down  the  rounded  surface 
of  the  adjacent  tooth.  For  instance,  let  A  (Fig.  4)  represent 
the  junction  of  the  two  upper  central  incisors,  B  represent  the 
frenum  of  the  gum  on  one  side,  and  C  represent  the  frenum  on  the 
other  side.  The  floss-silk  must  pass  through  the  junction  A ,  and 
shpping  and  sliding  across  the  rounded  side  of  the  tooth,  with  a 
drawing  motion  from  A  to  B,  must  then  scrape  across  the  gum 
to  the  frenum  C,  into  which  it  must  be  driven,  and  finally  scrape 
down  the  rounded  surface  of  the  tooth  from  C  to  ^ .  It  travels 
the  outline  of  a  triangle  (Fig.  4). 

The  mere  passing  of  the  thread  through  ^  in  a  straight  line, 
as  is  the  custom  of  most  people  who  use  floss-silk,  is  obviously 


PREVENTION   OF   MOUTH   INFECTION 


33 


ineffective,  since  the  bacteria  stick  to  the  sides  of  the  teeth  and 
gums  Uke  films  of  glue  and  can  only  be  removed  by  actual,  vigor- 
ous scraping.  The  mere  passage  of  the  silk  up  and  down  through 
A  is  as  useless  and  silly  a  performance  as  that  of  attempting  to 
cleanse  the  bacterial  masses  from  the  teeth  by  merely  rinsing 
them  with  a  wash.  A  mouth-wash  can  no  more  remove  the 
bacterial  masses  from  the  sides  of  the  teeth  than  it  could  remove 
a  coating  of  fresh  varnish  if  such  had  been  flowed  on  the  dried 


i^<.»i-ta.  ^  jiiiytrijif'  If 


Fig.  5 —Correct  position  of  hands  in  flossing  right  half  of  upper  dental  arch. 
Note  that  the  thumb  of  right  hand  is  on  the  outside. 


teeth  previous  to  the  cleansing.  This  adhesive  nature  of  the 
bacteria  must  be  recognized,  or  otherwise  successful  flossing  of 
the  teeth  will  be  impossible. 

In  cleansing  the  teeth  on  the  upper  right  side  the  thread 

should  be  stretched  between  the  index-finger  of  the  left  hand 

and  the  thumb  of  the  right  hand.    The  thumb  should  be  on  the 

outside  and  the  index-finger  on  the  inside  of  the  mouth  (Fig.  5). 

3 


34 


MODERN  DENTISTRY 


The  triangular  motion  should  then  be  carried  out  between  all 
the  teeth  all  the  way  back  to  the  farthest  molar,  care  being 
taken  to  see  that  the  thumb  slips  under  the  hp  when  the  molars 
are  reached.  When  this  has  been  accurately  done  there  will  be 
no  difficulty  in  reaching  behind  the  wisdom  tooth.  There  is  no 
instrument  yet  devised  that  can  hold  the  floss-silk  as  well  as  the 
fingers. 

When  we  come  to  cleansing  the  interdental  spaces  on  the 
upper  left  side  the  left  thumb  should  be  on  the  outside  and  the 


Fig.  6. 


-Correct  position  of  hands  in  flossing  left  half  of  upper  dental  arch, 
that  the  thumb  of  left  hand  is  on  the  outside. 


Note 


right  index-finger  should  be  on  the  inside  (Fig.  6) .  The  procedure 
for  cleansing  the  spaces  of  the  upper  left  side  is  the  same  as  for 
the  upper  right  side. 

In  cleansing  the  spaces  of  the  lower  right  side  the  free  silk 
must  extend  between  the  index-fingers,  the  right  index-finger 
being  on  the  outside  for  the  lower  right  side  (Fig.  7),  and  the  left 
index-finger  being  on  the  outside  of  the  teeth  for  the  left  lower 


PREVENTION   OF  MOUTH  INFECTION 


35 


side  (Fig.  8) .     In  other  respects  the  same  principle  for  cleansing 
the  spaces  is  to  be  observed. 

The  Method  of  Brushing  the  Teeth. — As  before  stated,  the 
tooth-brush  should  not  be  over  i|  inches  long,  the  bristles  not 
over  I  inch  long,  and  the  handle  long  and  large  enough  to  afford 
a  firm  grip  to  the  hand  (Fig.  9,  small  brush;  Fig.  10,  large  brush, 
which  is  obxdously  too  large).  The  principal  thing  to  be  avoided 
is  too  great  bristle  length,  since  long  bristles  by  increasing  the 


Fig.  7. — Position  of  hands  in  flossing  right  lower  side  of  dental  arch, 
the  index-finger  of  the  right  hand  is  on  the  outside. 


Note  that 


pivoting  arc  of  each  bristle  just  so  much  reduce  the  bristle 
friction  produced  by  the  general  movement  of  the  brush.  It 
is  bristle  friction  alone  that  cleanses  the  teeth  and  gums  during 
the  process  of  brushing.  Bristles  |  inch  long  can  pivot  f  inch 
each  way  without  bristle  friction.  If,  therefore,  there  is  a  i-uich 
stroke,  the  bristie  friction  stroke  is  only  I  inch,  and  if,  as  fre- 
quently happens,  the  tooth-brush  stroke  is  only  |  inch,  there  is 
no  bristie  friction  stroke  at  all.  The  i-inch  bristle,  under  the 
same  conditions,  would  have  a  play  each  way  of  1^  inch,  which 


36  MODERN   DENTISTRY 

theoretically  would  cause  only  f  inch  loss  of  bristle  friction,  but 
in  reality  it  would  be  less,  since  the  further  the  bristle  extends 
from  the  back  of  the  brush,  the  more  readily  it  bends  under 
pressure.  But  granting  that  there  was  f  inch  loss  in  bristle 
friction  to  each  stroke,  this  would  still  leave  a  real  cleansing 
friction  stroke  of  f  inch  when  the  i|-inch  brush  was  moved 
through  a  2|-inch  space,  the  amount  of  space  for  tooth-brush 
motion  usually  found  in  the  average  adult  mouth. 


Fig.  8. — Position  of  hands  in  flossing  the  left  lower  side  of  dental  arch.     Note 
that  the  index-finger  of  left  hand  is  on  the  outside. 

So  much  for  the  mechanics  of  tooth-brushing;  now  as  to  the 
actual  motions  as  appUed  to  the  human  mouth.  There  are  three 
motions:  First,  the  rotary  motion,  whereby  all  the  gums  and 
teeth  anterior  to  the  second  molars  are  cleansed  with  a  vigorous 
whirHng  action;  second,  the  drawing  motion,  wherein  the  middle 
of  the  brush  is  placed  behind  the  last  molar  and  drawn  vigorously 
across  the  outside  gum  margins  of  the  teeth;  third,  the  drawing 
motion,  wherein  the  brush  is  placed  back  of  the  last  molar  in- 


PREVENTION   OF   MOUTH   INFECTION  37 

side  of  the  mouth  and  drawn  sharply  forward  along  the  gum 
margins  and  the  teeth.  In  each  stroke  care  should  be  used  to 
follow  the  curve  of  the  arch  with  the  entire  face  of  the  brush. 


■■    UlUlllB 


jrig_  Q_ — Actual  size  of  brush  that  can  properly  cleanse  the  teeth  and  gums. 

Let  us  now  discuss  motion  No.  i  in  its  minute  details.  The 
upper  and  lower  front  teeth  should  be  placed  edge  on  edge  to 
avoid  the  lapping  of  the  upper  teeth  over  the  lower.  The 
brush  should  then  be  placed  against  the  teeth  and  rubbed  up- 


Fig   10. — Actual  size  of  brush  ordinarily  used. 

ward  to  the  junction  of  the  upper  gum  and  lip,  forward  for  a 
distance  of  a  full  inch  or  more,  downward  to  the  lower  gum  and 
lip  margin,  and  then  back  to  the  original  position,  as  shown  in 
Fig.  II.     This  should  be  done  at  least  five  or  six  times.     The 


38 


MODERN  DENTISTRY 


brush  should  then  be  placed  between  the  cheek  and  teeth  on  the 
left  side.  Here  the  same  general  motions  should  be  carried  out. 
The  brush  should  be  rubbed  upward  to  the  juncture  of  the  cheek 
and  gum,  back  to  where  the  end  of  the  brushing  is  stopped  by  the 


Fig.  II. — Motion  of  brush  for  cleansing  front  teeth  and  gums. 

overhanging  crr^^e  of  the  lower  jaw,  down  to  the  juncture  of  the 
cheek  and  lower  gum,  then  back  to  the  start,  as  in  Fig.  12.  This 
same  motion  should  be  repeated  on  the  right  side,  and  the  three 


Fig.  12. — Motion  of  brush  for  cleansing  side  teeth  and  gums. 


movements  of  motion  No.  i  are  finished.  If  after  this  motion  has 
been  thoroughly  performed  the  second  and  third  molars,  upper 
and  lower,  are  examined,  they  mil  still  be  found  covered  with 
bacterial  masses,  and  the  reason  for  these  undisturbed  deposits 


PREVENTION   OF   MOUTH  INFECTION  39 

is  easily  discovered.  The  curving  side  of  the  lower  jaw  lies  so 
close  to  the  upper  teeth  that  no  tooth-brush  can  effectively  get 
at  them  while  the  jaws  are  closed,  and  in  the  same  way  the  last 
two  lower  teeth  are  excluded  from  the  action  of  the  brush  by  the 
fact  that  they  he  behind  and  within  the  curving  angle  of  the  lower 
jaw.  When  the  jaws  are  closed  there  is  not  |  inch  room  remain- 
ing for  tooth-brush  cleansing,  but  when  the  jaws  are  partly 
opened,  the  lower  jaw  swings  back,  leaving  a  space  of  a  full  | 
inch  in  which  the  brush  can  thoroughly  do  its  work  behind  the 
third  molars.  ^  Therefore,  as  just  intimated,  in  performing 
motion  No.  2  for  the  upper  teeth  the  mouth  should  be  about  half 
open  and  the  Hps  and  cheek  held  relaxed.     The  middle  of  the 


Fig.  13.^ — Position  of  brush  preparatory  to  cleansing  upper  wisdom  teeth.      Dotted 
line  shows  direction  in  which  the  brush  should  be  drawn. 

bristles  of  the  i|-inch  brush  should  be  placed  at  the  back  of  the 
third  molar  and  drawn  briskly  forward  along  the  gum  margins, 
care  being  taken  to  follow  the  curve  of  the  gum  with  the  entire 
face  of  the  brush  (Fig.  13).  To  place  the  brush  behind  the 
third  molar  the  relaxed  corner  of  the  mouth  should  be  stretched 
back  by  the  back  of  the  brush  until  the  middle  of  the  brush 
is  directly  back  of  the  wisdom  tooth.  When  this  is  done  correctly 
the  brush  will  be  pointing  directly  at  the  wisdom  tooth  on  the 
other  side  of  the  arch.  The  middle  of  the  brush  should  be  placed 
behind  the  third  molar,  not  thrust  in  place  by  the  point,  as  by 
thrusting,  the  bristles  will  be  so  bent  that  the  resulting  pivoting 
,  of  the  bristles  will  cause  the  back  of  the  upper  third  molar  to  get 


40  MODERN  DENTISTRY 

no  bristle  friction  at  all,  and  so  the  back  of  the  third  molars  will 
not  be  cleansed.  Motion  No.  2  in  its  action  on  the  lower  molar 
teeth  is  exactly  the  same  as  with  the  upper,  except  that  instead 
of  placing  the  bristles  on  the  back  of  the  lower  third  molar,  the 
bristles  are  directed  downward  on  the  gum  back  of  the  third 
molar,  and  then  with  a  curving,  downward  sweep  are  brought 
sharply  along  the  gum  and  cheek  margins  and  the  necks  of  the 
lower  teeth  (Fig.  14).  This  motion  should  be  done  on  the  upper 
and  lower  jaws,  right  and  left,  and  not  less  than  five  or  six  times 
each. 

Motion  No.  3  is  comparatively  simple.     The  brush  is  placed 
on  the  gum  and  tooth  line  behind  the  third  molars  and  drawn 


Fig.  14. — Position  of  brush  preparatory  to  cleansing  back  of  lower  wisdom  teeth. 
Dotted  line  shows  the  proper  downward  sweep. 

sharply  forward  and  out  of  the  mouth  over  the  insides  of  the 
central  incisors,  care  being  taken  to  follow  the  curve  of  the  arch 
with  the  entire  face  of  the  brush.  The  brush  should  be  placed 
back  of  the  last  molars,  not  thrust  back  of  them,  as  thrusting  will 
cause  a  counterbending  of  the  brush  bristles  and  result  in  a 
pivoting  that  again  will  leave  the  back  molars  without  bristle 
friction,  and  consequently  dirty,  (Fig.  15).  Motion  No.  3  should 
be  done  five  times  on  the  upper  and  lower  jaws,  right  and  left, 
and  when  this  has  been  properly  done  the  surfaces  of  the  teeth 
and  gums  will  be  free  from  bacterial  masses. 

After  so  much  minute  explanation  it  may  not  be  inadvisable 
to  review  once  more  just  what  the  daily  cleansing  of  the  mouth 


PREVENTION    OF   MOUTH    INFECTION  4I 

should  be.  The  surfaces  between  the  teeth  should  be  thoroughly 
swept  by  floss-silk  to  remove  all  food  and  bacterial  deposits. 
The  teeth  and  gums  should  then  be  thoroughly  brushed,  as 
described,  with  dentifrice  or  antiseptic  mouth-wash  (see  Chapter 
III),  and  the  saliva  and  mouth-wash  vigorously  swashed  in 
between  the  teeth  for  a  period  of  not  less  than  two  minutes,  so 
that  the  thin  coating  of  bacterial  film  left  by  the  floss-silk  on 
the  sides  of  the  teeth  may  be  discouraged  from  growth  until 
the  next  cleansing.  Where  there  is  marked  gum  infection  a 
saturated  solution  of  sodium  silicofluorid  or  i  per  cent,  peroxid 
solution  should  be  held  in  the  mouth  for  at  least  two  minutes 


Fig.  15. — Position  of  brush  preparatory  to  cleansing  inside  of  dental  arches. 
The  brush  must  extend  well  back  of  the  back  tooth  and  be  drawn  briskly  forward 
along  the  edge  of  the  gum  and  teeth,  and  finally  out  across  the  median  line,  as  is 
shown  by  the  dotted  line. 

after  the  procedure  just  described.  This  cleansing  should  be 
carried  out  morning  and  evening.  It  must  not  be  forgotten, 
however,  that  each  mouth  is  a  separate  problem  and  must  be 
treated  as  such.  If  teeth  are  missing,  the  brush  must  be  inserted 
vigorously  in  the  vacant  spaces,  and  if  certain  abnormal  rotations 
are  necessary  the  dentist  must  train  the  patient  to  see  that  these 
abnormalities  are  met  and  the  parts  are  thoroughly  cleansed 
by  especially  devised  strokes  of  the  brush. 

Figure  i6  represents  a  pronounced  case  of  mouth  infection. 
An  examination  revealed  the  fact  that  the  infection  was  super- 
ficial in  the  gum  and  had  not  penetrated  along  the  teeth  so  as 


42  MODERN  DENTISTRY 

to  cause  abscesses  that  were  beyond  the  reach  of  the  floss-silk 
and  tooth-brush.  A  systemic  examination  proved  the  patient 
to  be  in  good  general  health.  The  patient  was  accordingly  told 
that  if  he  would  scrub  his  teeth  and  gums  according  to  the  author's 
directions,  and  also  use  floss-silk  as  described,  he  could  cure  him- 
self without  any  other  treatment  or  even  antiseptics.  The  patient 
came  back  in  four  days  and  another  photograph  was  taken  (Fig. 
17).  Note  the  wonderful  change  in  color,showing  that  the  gums 
had  become  almost  normal.  He  was  told  to  keep  up  the  floss- 
silking  and  gum-brushing,  and  not  to  use  any  dentifrice  or 
mouth-wash.  He  came  back  in  a  week,  and  while  his  mouth 
showed  considerable  improvement,  there  was  a  large  ulcer  still 
present.  The  author  told  him  that  by  this  time  he  expected  the 
mouth  to  be  entirely  well.  He  said,  "I  don't  know  what  more 
I  can  do,  doctor,  for  I  brush  my  gums  thoroughly  three  times  a 
day."  "Brush  them  once  a  day,"  was  the  reply,  "and  give  the 
poor  ulcer  a  chance  to  get  well."  In  this  instance  the  patient 
had  been  overstrenuous  in  carrying  out  instructions.  He 
went  away  and  in  four  days  more  returned,  and  the  third  picture 
(Fig.  18)  is  an  illustration  of  how  his  mouth  looked.  When  the 
author  first  saw  the  patient,  two  weeks  before,  his  gums  had 
the  color  of  Fig.  16,  and  would  bleed  at  the  touch  of  floss-silk 
or  a  brush.  Two  weeks  later,  through  proper  cleansing  alone, 
he  could  brush  them  as  vigorously  and  as  painlessly  as  he  could 
brush  his  finger-nails.  There  was  no  bleeding,  his  mouth  was 
healthy,  and  it  not  only  looked  clean,  but  it  felt  clean.  Mouth 
antiseptics  and  dentifrices  have  unquestionable  value  at  times, 
but  for  ordinary  service  their  value  is  inconsiderable  when  com- 
pared to  efficient  cleansing. 

In  closing  this  chapter  it  might  be  wise  to  emphasize  the  fact 
that  a  brush  softened  in  hot  water  is  a  valuable  instrument  with 
which  to  commence  to  cleanse  and  harden  infected  gums.  As 
the  gums  become  hard  and  firm  the  patient  will  naturally  be  less 
careful  about  the  use  of  hot  water  on  the  brush,  and  very  soon  the 
stiff  bristles  can  be  fearlessly  used.  This  precaution  is  especially 
valuable  in  the  preliminary  training  of  children  in  their  daily 
mouth  hygiene. 


Fig.  16. — Inflamed  gums  prior  to  using  dental  floss  and  tooth-brush  properly. 


CHAPTER  III 

A   STUDY   OF   TOOTH   ENAMEL   AND    SALIVA 

DENTIFRICES   AND   MOUTH-WASHES   IN   THEIR  RELATION   TO 
MOUTH   HYGIENE 

Enamel  Softening  and  Hardening. — Enamel  softening  has 
been  considered  to  be  necessarily  associated  with  roughening 
of  the  surface,  loss  of  luster,  and  dissolution  of  the  substance  that 
binds  the  enamel  rods  together ;  and  whenever  enamel  decalcifica- 
tion is.  associated  with  decay  of  dentin  this  conception  of  enamel 
softening  is  accurate.  But  this  conception  takes  into  considera- 
tion only  the  final  phase  rather  than  the  complete  process  of 
enamel  degeneration. 

Miller  and  many  others  in  producing  artificial  decalcification 
by  solvents,  in  employing  aqueous  solutions  of  acids  var)dng 
in  strength  from  |  to  2  per  cent.,  have  exposed  their  tests  to 
two  serious  objections:  First,  that  the  solutions  found  in  the 
mouth  are  saKva  solutions,  not  aqueous  solutions;  second,  that 
any  strength  greater  than  i  :  1000  of  lactic  acid  or  any  similar  acid 
would  practically  never  be  fdund  in  the  mouth.  Unquestionably, 
the  acid  set  free  from  the  bottom  of  a  bacterial  plaque  adherent 
to  the  enamel  may  be  acid  of  any  strength,  possibly  chemically- 
pure,  or  concentrated  acid  may  be  developed  in  a  cavity  where 
the  opening  into  the  mouth  is  small  enough  to  prevent  dilution 
with  saliva.  But  in  the  enamel  degeneration  which  is  associated 
with  general  erosion,  where  the  bacterial  plaque  is  not  an  impor- 
tant factor,  decalcification  tests  to  be  of  value  must  be  made 
with  saliva  solutions  and  with  acid  solutions  as  weak  as  those 
found  in  the  human  mouth;  for  saliva  itself  restrains  the  action 
of  many  acids  on  the  teeth  and  modifies  and  changes  the  appear- 
ance of  enamel  decalcification. 

For  instance,  i  :  1000  solution  of  lactic  acid  and  water,  at 
mouth  temperature,  will  cut  tooth  enamel  in  thirty  minutes, 

43 


44  MODERN   DENTISTRY 

producing  a  rough,  white  surface.  A  i  :  20,000  lactic  acid  aque- 
ous solution  will  at  the  end  of  three  or  four  days  leave  the  tooth 
enamel  unharmed  to  all  appearances,  and  yet  the  outer  surface 
of  the  enamel  will  be  found  with  the  edge  of  the  lancet  to  have 
distinctly  softened,  a  condition  which  is  only  found  with  a 
lactic  acid  and  saHva  solution  as  strong  as  i  :  500,  and  such 
a  solution  has  a  decidedly  acid  taste  and  turns  litmus  brilliantly 
red.  This  shows  that  ordinary  saliva  has  a  decided  protec- 
tive power  against  acids.  In  fact,  in  a  number  of  experiments 
with  lactic  acid  and  saliva,  a  i  :  500  solution  left  the  tooth  enamel 
absolutely  unharmed. 

The  action  of  aqueous  solutions  of  acid  calcium  phosphate 
and  acid  sodium  phosphate  on  the  teeth  has  been  mentioned  by 
various  observers,  extraordinary  stress  being  laid  on  the  fact 
that  these  acid  salts  cause  smooth  white  decalcification.  As 
a  matter  of  fact,  many  acids  in  aqueous  solutions  cause  smooth 
softening  if  the  solution  is  sufficiently  weak.  As  said  before, 
saHva  restrains  the  action  of  most  acids  up  to  a  certain  point, 
depending  upon  the  concentration  of  the  acid.  Beyond  this 
point  we  find  the  same  smooth  decalcification  that  we  have 
with  the  weak  aqueous  solutions,  and  finally  the  same  rough, 
white  decalcification  that  we  find  in  strong  aqueous  solutions  of 
acid.  The  saliva  solution  is  ordinarily  from  ten  to  twenty 
times  weaker  in  its  action  on  enamel  than  an  aqueous  solution 
of  the  same  acid  strength.  Acid  sodium  phosphate  and  acid 
calcium  phosphate  are,  however,  intensely  interesting  in  their 
action  not  only  in  aqueous  solutions  but  in  sahva  solutions. 
Acid  calcium  phosphate  (i  :  5000  aqueous  solution)  and  acid 
sodium  phosphate  (i  :  20,000  aqueous  solution)  at  the  end  of 
two  days  will-  turn  tooth  enamel  a  cloudy,  pearly  white,  with 
a  smooth  surface.  This  surface  is  perceptibly  softened  to  the 
cut  of  a  lancet.  If,  however,  the  tooth  enamel  is  removed  from 
the  solution  before  the  process  advances  too  far,  the  cloudy  ap- 
pearance will  in  time  disappear,  and  the  tooth  enamel  will  re- 
sume its  normal  appearance  and  hardness.  This  phenomenon 
occurred  so  consistently  not  only  with  the  acid  salts  mentioned, 
but  also  with  other  acid  solutions,  that  the  possibility  was  made 


A    STUDY    OF    TOOTH    ENAMEL   AND    SALIVA  45 

apparent  that  partially  softened  smooth  enamel  could  reharden 
of  itself  if  the  decalcification  had  not  progressed  too  far. 

The  following  test  was  therefore  made :  Two  sound  teeth  with 
enamel  impervious  to  the  lancet  were  each  placed  in  a  lobe  of 
an  orange.  These  lobes  were  each  placed  in  a  bottle  with  a 
few  drops  of  ether  to  prevent  fermentation,  and  kept  at  body 
temperature  for  two  days  in  an  incubator.  At  the  end  of  that 
time  the  teeth  were  removed  and  examined.  One  tooth  showed 
a  smooth,  white  translucent  area  of  decalcification,  running  from 
the  cutting  edge  to  about  one-third  of  the  distance  to  the  neck. 
The  rest  of  the  enamel  was  normal  to  all  appearances,  and  yet 
the  surface,  both  of  the  white  and  of  the  apparently  normal 
enamel,  was  readily  pared  with  a  lancet.  The  other  tooth 
seemed  normal,  but  here  again  the  outer  surface  of  the  tooth 
enamel  was  distinctly  softened.  This  difference  in  appearance 
was  undoubtedly  due  to  inherent  differences  in  the  enamel. 
These  teeth  were  then  washed  in  water  and  kept  in  a  specimen 
of  saliva  at  body  temperature  for  two  weeks.  At  the  end  of 
five  days  there  was  a  decided  rehardening  of  the  enamel  surface 
and  the  white  area  of  decalcification  had  half  disappeared. 
At  the  end  of  ten  days  the  enamel  could  no  longer  be  scratched 
with  a  lancet  at  the  end  of  two  weeks  the  white  spot  of  decal- 
cification had  almost,  if  not  entirely,  disappeared,  and  both  teeth 
appeared  perfectly  normal. 

The  question  then  arose  as  to  whether  the  carbon  dioxid  in 
the  saHva  was  or  was  not  a  cause  of  enamel  deterioration.  That 
saliva  does  possess  the  power  of  restraining  enamel  from  carbon 
dioxid  decalcification  was  proved  as  follows:  A  sound  extracted 
tooth  was  placed  in  an  automatic  soda  water  former  (Fig.  19) 
with  30  c.c.  of  saliva  which  had  been  obtained  by  chewing  rubber. 
The  saliva  was  then  charged  with  the  carbon  dioxid  and  the 
sparklet  placed  in  a  culture  oven  at  a  temperature  of  98°  F. 
for  thirty  days.  At  the  end  of  that  time  the  tooth  was  taken  out 
and  appeared  unharmed.  The  tooth  was  then  washed  and 
replaced  in  a  clean  siphon  with  distilled  water.  This  water 
was  then  charged  with  carbon  dioxid,  as  before,  and  replaced 
in  the  culture  oven  for  twenty-four  hours.    At  the  end  of  that 


46 


MODERN  DENTISTRY 


time  the  enamel  showed  a  chalky  decalcification  that  could  be 
scaled  off  with  the  finger-nail.     This  experiment  proved  that 

carbon  dioxid  does  not  attack  tooth 
enamel  in  the  presence  of  saliva. 

The  author  has  also  proved  that 
this  protective  power  of  saliva  is 
also  exerted  against  lemon,  orange, 
grape,  grape-fruit,  strawberry,  rhu- 
barb and  cherry.^ 

These  experiments  on  extracted 
teeth  with  weak  acid  solutions  and 
tests  with  a  sharp  lancet,  while 
suggestive,  did  not  seem  sufficient 
to  estabHsh  the  doctrine  that  soft- 
ened enamel  could  reharden;  so, 
while  morally  convinced  of  the 
truth  of  this  assertion,  I  immedi- 
ately started  to  perfect  a  machine 
that  would  show  in  the  minutest 
degree  just  how  far  a  given  force 
would  drive  a  standard  punch  into 
sound  enamel,  partly  decalcified 
enamel,  and  rehardened  enamel,  if 
such  a  rehardening  did  take  place. 
A  microdynamometer  (Figs.  20,  21) 
was  finally  devised  that  could  deliver 
475  pounds  pressure  on  a  punch,  the 
penetration  of  which  could  be  meas- 
ured up  to  1/600,000  inch.  Something 
approaching  this  accuracy  was  necessary,  as  it  was  found  experi- 
mentally that  the  scope  of  the  average  test  lay  usually  within 
1/100,000  inch.  It  was,  however,  decided  to  set  the  register  so 
that  it  would  measure  in  units  of  1/300,000  inch,  which,  as  can 
readily  be  seen,  could  be  reduced  by  a  table  to  microns  or  tenths 
of  microns,  i  micron  being  equal  to  1/25,000  inch;  twelve  of  the 
machine  units,  therefore,  being  equal  to  i  micron.     The  pres- 

^  Journal  of  the  Allied  Societies,  June,  1908. 


Fig.  19. — Type  of  soda 
water  former  used  in  testing 
the  power  of  saliva  to  restrain 
carbon  dioxid  from  attacking 
tooth  enamel. 


A   STUDY   OF   TOOTH   ENAMEL   AND   SALIVA 


47 


sure  was  given  by  a  mercury  gage  (9)  to  which  the  punch  (2) 
was  attached.  A  micrometer  screw  and  ratchet  wheel  (8), 
supporting  the  anvil,  was  strongly  connected  by  castings  and 


Fig.  20. — Microdynamometer.     (Author's  instrument.) 

heavy  drawn  steel  rods  beneath  to  the  mercury  gage  and  punch. 
On  this  anvil  rests  a  slab  (4)  with  parallel  sides  on  which  the  speci- 
men (i)  to  be  tested  was  placed.     The  pressure  was  applied  to 


48 


MODERN   DENTISTRY 


the  specimen  by  placing  it  on  the  anvil  and  raising  the  anvil 
by  the  micrometer  screw  and  ratchet  wheel  up  against  the  punch 
until  the  mercury  marked  the  pressure  desired.     The  penetration 


Fig.  21. — Detail  of  microdynamometer.     (Author's  instrument.) 


of  the  punch  into  the  specimen  was  made  known  by  a  microscope 
(6)  equipped  with  a  specially  constructed  filar  micrometer  (7), 
the  microscope  being  screwed  firmly  to  the  anvil.     This  microm- 


A    STUDY    OF    TOOTH    ENAMEL   AND    SALIVA  49 

eter  was  then  adjusted  and  set  so  that  it  could  accurately  divide 
into  the  desired  number  of  parts  a  glass  scale  (3)  attached  to  the 
punch.  By  this  device  all  error  in  the  use  of  the  machine  was 
largely  thrown  uot,  since  only  the  relation  between  the  punch 
and  the  anvil  was  within  the  scope  of  measurement.  In  Figs. 
20  and  21  the  numbers  11,  12,  and  13  represent  the  counter- 
weight for  the  mercury  gage,  the  ratchet  screw  for  raising  or 
lowering  the  glass  scale,  and  specimens  prepared  for  use. 

In  making  the  various  tests  three  punches  were  used :  a  heavy 
steel  punch  with  a  flat  hardened  circular  point,  0.02  inch  in 
diameter;  an  iridium-pointed  punch  for  testing  acid  erosion, 
0.02  inch  in  diameter  and  standing  25  pounds  pressure  without 
showing  compression;  a  diamond-pointed  punch  with  a  circular, 
flat  point,  0.02  inch  in  diameter  that  could  be  used  in  acid  solu- 
tions and  would  readily  stand  100  pounds  pressure — 25  pounds 
pressure  with  the  diamond  point  gives  a  penetration  equal  to 
75  pounds  with  the  steel  point.  This  is  no  doubt  due  to  the 
greater  sharpness  of  the  diamond  edge  over  the  steel. 

If,  therefore,  the  specimen  is  so  adjusted  and  set  under  pres- 
sure that  there  will  be  no  give  between  it  and  the  anvil,  it  is  pos- 
sible to  determine  accurately  within  one-tenth  of  a  micron  just 
how  far  the  punch  wiU  penetrate  under  a  given  pressure.  For 
instance,  the  specimen  is  carefully  ground  with  a  specially  adapted 
section  grinder  (Fig.  22),  so  that  there  is  a  flat,  large  base.  A 
small  spot  bn  the  top  of  the  enamel  is  ground  parallel  to  the  base. 
This  forms  the  area  to  be  tested.  Any  pressure  exerted  on  the 
enamel  spot  by  the  punch  is  directly  expended  on  the  enamel 
without  any  side  give  between  the  base  of  the  specimen  and  the 
anvil.  The  specimen  with  parallel  sides  is  placed  on  an  agate 
slab  with  parallel  sides  (4)  and  the  slab  placed  on  the  anvil. 
The  steel  punch,  let  us  suppose,  is  adjusted  near  the  edge  of  the 
ground  enamel  and  given  a  pressure  of  5  pounds.  A  reading 
by  the  microscope  attached  to  the  anvil  is  then  taken  on  the  scale 
attached  to  the  punch.  The  pressure  is  then  raised  to  the  de- 
sired amount,  say  75  pounds,  for  a  given  time,  and  then  the  pres- 
sure is  reduced  again  to  5  pounds  and  another  reading  taken, 
the  difference  on  the  scale  representing  the  penetration  of  the 


50 


MODERN  DENTISTRY 


punch.  To  shift  the  specimen  under  the  point  for  the  different 
measurements  the  agate  slab  is  moved,  not  the  specimen  on  the 
slab.  This  eliminates  variations  in  the  spring  of  the  specimen, 
since  the  compression  of  the  parallel  slab  on  the  anvil  under  a 
given  pressure  will  always  be  the  same. 


Fig.  22. — A,  Motor;  B,  stone  for  grinding  specimen  cemented  to  tlae  platen  C, 
D,  micrometer  screw  for  raising  and  lowering  the  specimen;  E,  water  tank  with 
tube  for  conveying  water  to  the  stone  in  motion;  F,  handle  that  swings  specimen 
backward  and  forward  across  stone  in  motion. 


Five  or  more  measurements  were  usually  made  for  each  speci- 
men and  the  average  taken.  By  this  means  the  hardness  and 
strength  of  normal  enamel  can  be  shown,  as  can  also  the  varia- 
tions from  the  normal  enamel  caused  by  strong  acids,  watery 
solutions  of  acids,  saKva,  fresh  and  stale,  and  acid  saliva  solu- 


A   STUDY   OF   TOOTH   ENAMEL  AND   SALIVA  51 

tions;  and  the  recovery  of  enamel  when  removed  from  such 
solutions. 

AU  analytic  analyses  of  saliva  heretofore  have  been  hampered 
by  the  fact  that  the  investigator  started  by  first  chemically  break- 
ing it  up,  thus  largely  destroying  it  as  saliva.     All  analytic 
investigation  of  saliva  from  a  dental  point  of  view  up  to  the  pres- 
ent time  has  been  inconclusive,  owing  to  the  fact  that  normal 
saliva  may  be  alkaline  to  lacmoid  or  congo  red,  neutral  to  Htmus, 
and  acid  to  turmeric  paper,  all  at  the  same  time.     How  saHva 
reacts  to  lacmoid,  litmus,  or  turmeric  may  be  purely  of  academic 
interest,  but  how  it  may  act  on  enamel  and  dentin  is  a  vital 
question,  and  this  machine  has  opened  the  way  for  enamel  to 
be  its  own  indicator  of  how  a  saHva  may  affect  it.     Since  the  first 
days  of  physiologic  study,  saliva  has  been  a  most  tempting  field 
for  investigation  because  it  is  the  body  secretion  most  easily 
obtained  in  a  living  state.     To  the  diagnostician  it  no  doubt 
eventually  will  be  at  least  of  equal  value  to  urine,  but  up  to  the 
present  time  it  has  not  been.     This  may  be  due  to  the  fact  that 
saliva  is  a  living  substance,  and  urine  an  effete  product  that 
lends  itself  to  a  chemical  analysis  that  would  absolutely  destroy 
saliva  as  saliva.     Chemical  analysis  that  breaks  up  the  indi- 
viduahty  of  living  saliva  is  of  little  more  value  in  showing  the 
vital  action  of  saliva  than  fried  chicken  would  be  in  showing  the 
beauties  of  a  cock-fight.     I  am  far  from  discouraging  saHva 
analysis  of  any  kind.     Salivary  extracts  or  chemical  products 
are  interesting,  but  inconclusively  related  to  the  living  action  of 
the  secretion ;  and  therefore,  while  enzymes  of  a  curious  and  even 
therapeutic  nature  may  be  extracted  from  saliva,  no  one  can  prove 
that  they  justly  represent  the  action  of  the  living  secretion 
unless  some  means  are  devised  to  make  control  tests  with  the 
living  saKva  that  show  a  corresponding  action.    The  machine 
just  described  makes  it  possible  to  test  the  acid-restraining  power 
of  various  living  salivas  on  tooth  enamel  in  relation  to  a  standard 
water  solution  of  acid.     Salivas  vary  in  this  power.    The  same 
saliva  may  vary  at  different  times,  apparently  according  to  the 
condition  of  the  patient. 

The  conditions,  then,  are  as  follows:  During  sickness  the  teeth, 


52  MODERN  DENTISTRY 

from  clinical  experience,  are  known  to  decay.  This  may  be  due 
partly  to  acid  medicine  or  lack  of  care,  but  with  every  allowance 
for  these  sources  of  error  it  seems  to  be  well  estabHshed  that  severe 
or  chronic  illness  in  some  way  may  render  the  teeth  susceptible 
to  deterioration.  If  a  relation  between  approaching  sickness 
and  a  loss  of  acid-protecting  power  in  the  saliva  could  be  estab- 
lished, a  beginning  in  the  diagnostic  testing  of  the  Kving  saliva 
would  have  been  fairly  inaugurated. 

Take,  for  example,  the  following  test  that  was  made  on  a 
specimen  of  tooth  enamel:  One  side  was  ground  to  a  fiat,  broad 
base;  on  the  other  side  the  enamel  was  ground  in  a  small  cor- 
responding parallel  plane.  This  was  placed  on  the  anvil  of  the 
machine  and  raised  up  against  an  iridium  point,  0.02  inch  in 
diameter,  until  a  pressure  of  5  pounds  was  reached.  A  read- 
ing was  then  taken  on  the  micrometer  scale  and  noted.  The 
anvil  was  raised  up  and  down  repeatedly  until  all  give  between 
the  specimen  and  the  anvil  disappeared,  and  the  5  pounds  pres- 
sure always  gave  the  same  reading.  Then  fresh  lemon  juice 
and  water,  i  :  100,  was  placed  on  the  specimen  around  the  point 
and  the  point  relaxed  so  that  the  fluid  could  readily  get  under- 
neath. At  certain  intervals  of  time  the  pressure  of  5  pounds 
was  tried  and  a  reading  taken,  which  showed  a  loss  of  tooth 
structure  as  follows: 

2  minutes 0.8  microns 

5  minutes 1.2       " 

10  minutes 1.4       " 

35  minutes 2.3       " 

60  minutes 2.8       " 

Thus,  in  one  hour  there  was  a  loss  of  2.8  microns  of  tooth 
enamel.  This  same  test  was  then  made  on  the  same  tooth 
enamel  with  a  fresh  saliva  solution  of  lemon  juice,  i  :  100. 
This  solution  turned  litmus  red  and  was  distinctly  sour,  and  yet 
after  an  hour's  application  the  enamel  showed  a  loss  of  only  0.3 
micron.  We  might,  therefore,  express  the  restraining  factor  of 
the  saliva  as  28  :3.  Numerous  other  tests  have  been  made  of 
a  similar  nature  and  all  seem  to  give  consistent  figures.  They 
almost  invariably  show  the  power  of  saliva  to  restrain  the  action 


A    STUDY    OF    TOOTH   ENAMEL   AND    SALIVA  53 

of  acid  on  enamel.   They  also  show  that  some  enamels  are  much 
more  resistant  to  decalcifying  action  than  others. 

As  an  illustration  another  test  might  prove  interesting: 
The  specimen  was  ground  longitudinally  for  a  base  along  its 
axis  and  a  small  parallel  plane  ground  on  the  enamel  of  the  op- 
posite side.  A  solution  of  i  :  loo  lemon  juice  and  water  applied 
for  an  hour  dissolved  the  enamel  i  micron;  i  :  loo  solution  of 
lemon  juice  and  saKva  applied  for  sixteen  hours  showed  no 
loss  of  tooth  tissue  at  all.  It  was  then  tested  with  the  steel 
punch  for  hardness  and  was  found  so  softened  that  more  than 
60  pounds  pressure  could  not  be  withstood.  The  softened  enamel 
simply  refused  to  support  the  punch  under  such  a  pressure.  The 
specimen  was  then  placed  in  fresh  saliva,  and  set  in  the  culture 
oven  at  blood  heat  for  seven  hours,  the  saliva  being  changed 
every  half-hour.  At  the  end  of  that  time  the  tooth  was  again 
tested  with  the  steel  punch  and  was  found  to  have  so  hardened 
that  75  pounds  pressure  was  readily  withstood  and  a  various 
penetration  noted  of  3.5,  2.8,  3.2,  and  4.5  microns. 

Further  tests  made  on  sound  enamel  without  the  use  of  acids 
show  conclusively  that  the  substance  of  normal  enamel  is  much 
harder  on  the  outside  surface  than  within,  where  it  is  not  exposed 
to  the  air  or  saKva.  Surfaces  tested  immediately  after  grinding 
have  been  known  to  harden  from  15  to  30  per  cent,  when  immersed 
in  saliva  or  exposed  to  the  air  for  a  period  of  a  few  hours  or  a 
day.  These  tests  have  been  repeated  and  have  given  results 
so  consistent  that  the  author  feels  that  they  are  conclusive. 

This  softening  and  hardening  of  enamel  has  a  very  practical 
bearing  in  relation  to  mouth  cleansing  and  the  use  of  brush  and 
dentifrices.  Enamel  that  in  its  hardest  state  would  only  show 
insignificant  wear  to  dentifrice  may,  in  a  softened  state,  lose  a 
very  material  amount  of  tooth  structure.  This  softening  and 
hardening  may  readily  account  for  the  fact  that  some  patients, 
especially  those  fond  of  fruit,  wear  their  teeth  down  at  a  com- 
paratively early  age.  The  mere  friction  of  mastication  is  suf- 
ficient to  take  off  a  layer  of  enamel  softened  by  fruit  or  vinegar. 
This  seems  to  me  a  sufficient  argument  against  mouth-washes 
based  on  fruit  acids  or  vinegar.     I  am  convinced  that  enamel 


54 


MODERN  DENTISTRY 


will  harden  and  soften  within  certain  Umits  and  that  this  harden- 
ing and  softening  is  influenced  by  the  saliva  and  food-stuffs. 
I  also  believe  the  same  is  true  of  dentin,  but  so  far  the  tests 

concerning  this  are  not  suffi- 
ciently numerous  to  serve  as 
a  basis  for  a  positive  asser- 
tion. 

Force  Required  in  Masti- 
cation.— The  following  experi- 
ments were  undertaken  to 
determine  the  amount  of 
triturating  force  required  to 
chew  food,  especially  meat. 
For  the  mastication  tests  a 
natural  skull  with  practically 
perfect  molars  of  average  size 
was  cast  in  bronze.  The 
skull  was  so  arranged  that  all 
of  the  mastication  was  done 
with  two  lower  molars  and 
their  occluding  teeth. 

The  bronze  skull  was 
clamped  to  a  platform  (Fig. 
22,,  A).  B  represents  a  cross- 
bar under  the  jaws  so  ar- 
ranged that  the  force  applied 
by  the  spring  balance,  C, 
will  be  applied  directly  to  the 
first  and  second  molars  on  the 
left  side  of  the  j  aw.  The  force 
of  mastication  is  then  applied  through  the  lever,  D,  and  registered 
by  the  needle,  E.  The  skull  is  placed  at  such  an  angle  to  the 
force  that  a  triturating  motion  is  given  as  the  jaws  come  together. 
F  represents  the  handle  by  which  the  lower  jaw  can  be  guided 
by  the  hand  of  the  operator  up  to  the  time  the  actual  force  of 
mastication  is  applied.  The  first  experiments  were  with  bread. 
Dry,  crisp  crusts  broke  at  15  pounds  pressure;  but  a  mixture  of 


Fig.  23. — Machine  for  measuring  the 
force  required  for  mastication.  (Author's 
instrument.) 


A   STUDY   OF   TOOTH  ENAMEL   AND    SALIVA  55 

soft  inside  and  crust,  such  as  we  ordinarily  find,  could  not  be 
bitten  through  with  a  force  of  loo  pounds.  The  crust  and  in- 
side formed  a  dense  immovable  mass,  but  when  a  Httle  saliva 
was  placed  on  this  same  mass,  it  was  readily  masticated  with  a 
force  of  3  pounds.  Asparagus,  roast  onion,  peas,  and  roast 
potato  were  chewed  with  i  to  2  pounds  pressure.  Raw  cabbage 
required  a  pressure  of  16  pounds;  raw  onion,  4  pounds;  head 
lettuce,  8  pounds;  whole  radishes  broke  at  from  20  to  25 
pounds,  while  pieces  broke  at  from  10  to  15  pounds. 

This  gives  a  fair  idea  what  triturating  force  is  required  for 
the  mastication  of  vegetables. 

Following  is  a  table  of  the  triturating  forces  necessary  to 
masticate  meat: 

Pounds 

Corned  beef 18  to  22 

Boiled  beef 3 

Tongue i  to  2 

Lamb  chop 16  to  20 

Roast  lamb 4 

Roast  lamb  kidney 3 

Tenderloin  of  beefsteak,  very  tender 8  to  9 

Sirloin  steak 10,  20,  43 

Beef,  bottom  of  round,  tough    38  to  42 

Roast  beef 20  to  35 

Boiled  ham 10  to  14 

Broiled  ham i  o  to  13 

Pork  chops 25  to  30 

Roast  veal 16 

Veal  chops 12 

Roast  mutton 18  to  22 

Dr.  Black's  tests  have  shown  that  the  human  jaws  can  exert 
a  pressure  of  from  150  to  300  pounds.  I  show  here  a  man  biting 
340  pounds  on  a  gnathodynamometer  (Fig.  24).  The  force 
reqmred  to  crack  a  hazel  or  pecan  nut,  such  as  the  ordinary 
urchin  breaks  with  ease,  is  100  to  230  pounds.  These  tests,  of 
course,  are  not  recommended  unless  the  teeth  are  exceptionally 
strong  and  the  sockets  absolutely  healthy,  for  if  the  teeth  are 
sensitive  to  pressure  the  jaws  will  instinctively  avoid  their  full 
force.  It  is,  therefore,  clear  that  thorough  mastication  and  hence 
proper  digestion  of  the  food  is  only  possible  when  the  teeth  are 


56 


MODERN  DENTISTRY 


sound  and  the  gums  free  from  infection;  and  such  a  condition 
of  the  teeth  and  gums  can  only  be  maintained  through  scientific 
mouth  hygiene. 

Dentifrices  and  Mouth-washes. — As  stated  in  Chapter  II, 
mechanical  cleansing  of  the  bacterial  masses  will  reduce  the  germs 
to  an  insignificant  number  and  it  will  also  cause  an  auto-inocula- 
tion by  rubbing  the  infection  into  the  tissues,  thus  stimulating 
them  to  form  protective  bacterial  ferments.  The  ferments  thus 
formed  are  so  effective  in  restoring  inflamed  tissues  to  health 


Fig.  24. — Gnathodynamometer  for  measuring  the  force  exerted  by  the  closing  of 
the  jaws.    This  represents  a  man  biting  340  pounds — over  twice  his  weight. 


that  all  other  means  for  combating  the  invading  infection  sink 
into  secondary  importance.  Thus  the  blood-serum  thoroughly 
charged  with  protective  antibodies  might  justly  be  termed  the 
most  effective  mouth- wash  at  our  disposal;  for  this  mouth-wash 
by  its  very  nature  is  most  readily  appHed  to  the  invading  hosts 
even  when  they  have  penetrated  deeply  below  the  surface  of  the 
mucous  membrane. 

And    yet   there   are   certain   mouth-washes   and   antiseptic 
dentifrices  that  can  be  used  to  effectively  supplement  the  pro- 


A    STUDY    OF    TOOTH    ENAMEL   AND    SALIVA  57 

tective  elements  of  the  blood,  but  they  must  be  considered  purely 
supplementary  in  their  action.  Any  chemical  mouth-wash 
sufficiently  strong  to  kill  bacterial  masses  in  the  time  permitted 
for  its  apphcation  in  the  mouth  must  be  strong  enough  to  be 
poisonous  to  the  tissues,  and  such  a  result  is  apt  to  weaken  the 
resistance  of  the  tissue  cells  against  further  bacterial  attacks. 
Effective  mouth-washes  and  antiseptic  dentifrices  should  co- 
operate with  the  curative  action  of  the  tissue  cells  without 
weakening  them. 

Heretofore  this  important  principle  underlying  the  use  of 
antiseptics  has  not  been  sufficiently  understood.  Strong  anti- 
septics, as  washes,  have  been  used  without  the  prehminary 
mechanical  removal  of  the  bacterial  masses  in  the  vain  expecta- 
tion that  the  strong  germicidal  wash  would  be  able  to  destroy 
and  wash  the  adhesive  colonies  away.  Under  these  conditions 
the  exterior  portions  of  the  sticky  masses  of  germs  alone  are  killed, 
leaving  the  infection  unharmed  beneath  the  surface  of  the  bac- 
terial plaque  to  continue  its  attacks  on  the  tissues  with  which 
it  is  in  contact.  And  the  rest  of  the  mucous  membrane  of  the 
mouth,  which  was  not  covered  by  the  bacterial  plaques,  continues 
to  have  its  bacterial  resistance  lowered  by  the  use  of  the  strong 
antiseptic,  and  is  rendered  more  Hkely  to  accept  infection  after 
the  protective  action  of  the  strong  antiseptic  has  been  dissipated 
by  the  oral  fluids. 

In  addition  to  the  bactericidal  action  of  the  blood  there  are 
at  least  three  health-restoring  processes  in  the  mouth.  First, 
a  substance  that  is  present  for  the  specific  purpose  of  special 
protection,  which  is  illustrated  by  the  saliva's  power  of  retarding 
enamel  decalcification;  the  second  consists  of  an  automatic 
power  of  resistance  and  self-repair,  which  is  illustrated  by  the 
power  possessed  by  tooth  enamel  to  reharden  after  partial 
decalcification  by  acids;  third,  its  power  to  reharden  the  surface 
when  its  soft  under  substance  is  exposed  by  attrition  to  the 
saliva  or  air. 

Salivas  have  different  protective  properties,  and  the  saliva  in 
the  same  mouth  will  show  a  great  variation  in  its  preservative 
power  under  various  conditions  of  the  system.     It  is  possible  that 


58  MODERN  DENTISTRY 

gout,  diabetes,  tuberculosis,  arteriosclerosis,  or  even  a  bad  attack 
of  grip,  may  reduce  the  vitality  of  the  agencies  resisting  enamel 
deterioration. 

It  will  be  noted  by  the  careful  observer  that  many  mouth- 
washes, such  as  solutions  of  chlorate  of  potash,  peroxid  of  hydro- 
gen, and  sodium  silicofluorid,  have  wonderfully  healing  prop- 
erties in  the  mouth,  and  yet  in  the  dilutions  used  in  the  mouth 
they  have  not  apparently  any  marked  germicidal  action.  Thus 
we  have  had  up  to  the  present  time  a  supposedly  irreconcilable 
difference  between  cHnical  experience  and  laboratory  research. 
But  fortunately  the  wonderful  researches  of  Ehrlich^  concerning 
the  germicidal  action  of  salvarsan  have  thrown  light  on  this 
most  important  subject.  EhrHch  found  that  the  syphilis  germs 
exposed  to  the  action  of  salvarsan  were  neither  destroyed  nor 
rendered  in  any  way  different  as  regards  appearance  or  activity, 
but  that  they  were  nevertheless  sensitized,  so  that  the  white 
corpuscles  of  the  blood  could  eat  them  in  a  way  impossible  to 
syphilis  germs  that  had  not  been  subjected  to  the  action  of  sal- 
varsan. He  then  formulated  the  principle  that  germs  might 
be  sensitized  by  a  comparatively  inert  drug,  so  that  the  bacterial 
action  of  the  tissues  or  blood  might  digest  them.  The  effective 
non-germicidal  agents,  such  as  chlorate  of  potash,  peroxid  of 
hydrogen,  and  sodium  silicofluorid,  probably  act  on  this  principle. 

Recent  experiments  under  the  supervision  of  Dr.  A.  P. 
Kitchens  indicate  that  a  i  per  cent,  peroxid  solution  has  the  same 
strength  in  inhibiting  the  growth  of  typhoid  bacilli  as  a  i  per 
cent,  carbolic  acid  solution.  This  action,  while  non-germicidal, 
is  a  valuable  scientific  fact,  and  is  particularly  interesting  in 
reference  to  the  antiseptic  action  of  certain  oxygen-Kberating 
dentifrices  which  claim  to  cleanse  the  mouth  by  the  development 
of  hydrogen  peroxid.  The  idea  is  so  excellent  that  it  should  be 
given  encouragement  by  both  pharmacists  and  the  public  at 
large,  but  as  yet  none  of  the  widely  exploited  peroxid-forming 
dentifrices,  according  to  the  analyses  that  have  come  to  my 
notice,  have  ever  been  able  to  develop  more  than  0.5  per  cent, 
free  oxygen.  This,  as  can  be  shown  mathematically,  cannot 
iThe  Lancet,  August  16,  1913. 


A   STUDY   OF   TOOTH   ENAMEL  AND   SALIVA  59 

form  more  than  35  minims  of  the  standard  3  per  cent,  peroxid 
solution  for  each  100  grains  of  dentifrice.  The  amount  of 
tooth-powder  capable  of  being  put  on  an  average  tooth-brush 
is  seldom  as  much  as  10  grains,  which  10  grains  or  less  of  powder 
would  have  to  be  depended  upon  to  deliver  the  antiseptic  action 
to  the  mouth.  These  10  grains  of  tooth-powder,  under  the  most 
favorable  conditions,  would  then  deliver  3I  drops  of  the  ofi&cial 
peroxid  solution,  no  more;  3I  drops  or  even  5  drops  would  be 
palpably  inadequate  to  have  any  effect  in  the  mouth.  Some 
of  these  preparations  that  have  been  claimed  to  have  the  power 
of  sterilization  by  free  oxygen,  under  analysis  did  not  show  the 
presence  of  free  oxygen  at  all.  This  was  due  to  some  error  in 
the  manufacture,  no  doubt,  but  for  practical  antisepsis  in  the 
mouth  it  really  made  little  difference,  as  3  drops  of  peroxid 
of  hydrogen  would  be  so  rapidly  diluted  and  broken  up  by  the 
oral  fluids  that  its  antiseptic  value  in  the  course  of  half  a  minute 
could  be  hardly  much  more  effective  than  so  much  distilled  water. 
Peroxid  of  calcium  and  peroxid  of  strontium,  as  recommended 
by  many  writers,  are  entirely  too  caustic  to  be  used  pure  in  the 
mouth.  When  placed  in  any  quantity  on  the  tongue  they  make 
a  bad  burn  that  lasts  for  days.  However,  the  commercial  prep- 
aration of  peroxid  of  magnesium  is  especially  bland  and  effec- 
tive. It  comes  diluted  with  magnesium  hydroxid  and  carbonate, 
so  that  it  variously  yields  from  4  to  7  per  cent,  free  oxygen,  and 
is  only  soluble  in  about  15,000  parts  of  water — practically  in- 
soluble. This  powder  can  be  freely  taken  into  the  mouth  in 
any  quantity,  hberating  for  every  100  grains  enough  oxygen 
to  make  280  to  500  drops  of  a  3  per  cent,  alkaline  peroxid  solu- 
tion. The  commercial  powder  has  just  about  the  cutting  grit 
of  precipitated  chalk,  and  when  finely  powdered,  practically 
none  at  all.  When  it  is  evacuated  from  the  mouth  large  quanti- 
ties adhere  to  the  interstices  and  necks  of  the  teeth.  This 
tendency  may  be  turned  to  great  advantage  by  the  patient,  for 
while  this  powder  is  practically  insoluble  in  water,  it  is  readily 
converted  into  a  soluble  magnesium  salt  by  any  acid  that  may 
chance  to  be  present.  Perborate  of  soda,  as  will  be  shown 
shortly,  has  no  grit  at  all. 


6o  MODERN  DENTISTRY 

But  now  let  us  discuss  the  question  of  abrasives  in  denti- 
frices. AH  thoughtful  dentists  must  have  noticed  that  there 
is  a  terrible  loss  of  enamel  in  the  mouths  of  those  who  are  par- 
ticularly careful  of  their  teeth,  and  this  appears  generally  be- 
tween the  ages  of  forty  and  fifty  and  is  made  manifest  by  the 
complete  disappearance  of  the  enamel  in  ever-spreading  foci 
on  the  labial  surfaces  of  the  front  teeth.  This  has  been  explained 
by  many  as  arising  from  gout,  rheumatism,  the  absence  of  the 
sulphocyanates  in  the  sahva  or  an  excess  of  acid  calcium  phos- 
phate. A  systemic  cause  may  be  partly  responsible  for  this 
condition,  but  the  author  does  not  know  of  a  single  case  of  such 
erosion  in  the  mouth  of  a  patient  who  did  not  use  tooth-powder 
excessively  and  who  was  not  abnormally  fond  of  acid  fruits. 
As  the  loss  of  the  enamel  is  confined  almost  entirely  to  incisors, 
canines,  bicuspids,  and  first  molars,  it  would  seem  strange  that 
a  disease  wholly  systemic  should  not  attack  all  of  the  teeth  of 
the  mouth  with  equal  impartiality. 

Destructive  Action  of  Dentifrices. — In  1908  I  pubHshed  in 
the  Dental  Brief  experiments  showing  the  effect  of  grits  on  the 
teeth,  proving  that  tooth-powders,  even  of  chalk,  were  largely 
instrumental  in  cutting  the  well-known  smooth  grooves  in  the 
necks  of  teeth,  that  so  frequently  appear  from  second  molar  to 
second  molar.  These  characteristic  grooves  were  readily  re- 
produced on  extracted  teeth  out  of  the  mouth.  At  that  time ,  from 
experiments  made  with  a  brush- wheel  and  pumice,  I  erroneously 
thought  that  grits  had  no  effect  on  the  enamel  of  the  grinding 
surfaces.  Although  these  tests  were  judged  only  from  their 
macroscopic  effect,  and  no  measuring  instrument  of  precision 
was  used,  and  although  they  were  faulty,  inasmuch  as  they  did 
not  reveal  the  full  extent  and  significance  of  the  destructive  action 
of  pumice,  chalk,  etc.,  they  were  the  beginning  of  my  investiga- 
tions in  this  field.  Later  on  a  series  of  experiments  was  under- 
taken to  determine  just  what  would  happen  to  the  enamel  and 
cementum  of  a  tooth  when  brushed  with  an  ordinary  tooth- 
brush and  saliva;  when  brushed  with  certain  mouth-washes; 
when  brushed  with  certain  proprietary  dentifrices;  and  finally, 
what  happened  when  brushed  with  plain  precipitated  chalk. 


A    STUDY    or    TOOTH    ENAMEL   AND    SALIVA  6 1 

In  each  instance  the  loss  of  tooth  substance  was  carefully  deter- 
mined by  an  especially  constructed  Brown  &  Sharpe  micrometer. 
The  first  test  was  made  to  determine  the  effect  of  brushing 
the  enamel  and  cementum  for  ten  minutes  with  a  new  brush 
and  saliva  alone.  Many  such  tests  showed  that  the  brush  and 
saliva  seemed  to  have  no  harmful  effect  on  cementum  or  enamel. 
Six  of  the  most  prominent  and  best  advertised  dentifrices  were 
then  tested,  a  new  brush  being  used  with  saliva  and  dentifrice 
for  each  test,  the  brushing  being  continued  for  ten  minutes: 
Dentifrice  No.  i  cut  off  o.oooi  inch  of  enamel  and  from 
0.0023  to  0.0083  i^^ch  of  cementum. 

Dentifrice  No.  2  gave  a  loss  of  0.0001  inch  of  enamel  and 
0.0026  inch  of  cementum. 

Dentifrice  No.  3  gave  no  loss  of  enamel  and  a  loss  of  0.0066 
inch  of  cementum. 

Dentifrice  No.  4  gave  a  barely  measurable  loss  of  enamel  and 
0.012 1  inch  of  cementum. 

Dentifrice  No.  5  caused  no  loss  of  enamel  and  0.0073  i^^ch  of 
cementum. 

Dentifrice  No.  6  caused  no  loss  of  enamel  and  0.0007  i^ch  of 
cementum. 

The  only  reason  the  powders  with  grit  are  so  popular,  in  my 
opinion,  is  because  they  make  the  front  teeth  presentable  with 
a  minimum  amount  of  labor.  The  unsatisfactory  results  are 
partly  due  to  laziness  and  partly  due  to  the  inefficient,  un- 
scientific teaching  of  the  profession,  who  have  recommended 
methods  of  tooth-brushirtg  that  a  simple  inspection  of  the 
mouth  will  show  do  not  cleanse  the  teeth. 

Having  investigated  some  of  the  prominent  proprietary 
dentifrices,  I  next  applied  the  same  tests  to  the  standard  chemical 
substances  that  might  prove  of  value  in  mouth  prophylaxis. 
I  found,  as  would  be  expected,  that  ordinary  chalk  would  cut 
the  cementum  and  enamel.  Thinking  there  might  be  an  excess 
of  sihca  in  it,  precipitated  chalk,  guaranteed  to  be  free  from  silica, 
was  procured  from  a  standard  chemical  company.  It  seemed 
to  cut  more  than  the  others.  The  abrasive  action  of  peroxid 
of  magnesium  was  next  tried  and  it  was  found  that  in  its  coarse 


62  MODERN  DENTISTRY 

state  it  had  a  friction  grit  on  the  enamel  and  cementum  some- 
what less  active  than  precipitated  chalk,  but  nevertheless  a 
decided  grit.  When,  however,  the  peroxid  of  magnesium  was 
ground  in  an  agate  mortar  to  impalpabihty  no  such  erosion  was 
attained,  thus  showing  that  in  peroxid  of  magnesium  we  can  have 
a  grit  slightly  less  than  chalk  down  to  almost  no  grit  at  all,  and 
also  a  tooth-powder  that  will  give  abundant  oxygen.  I  next 
tried  the  frictional  action  of  perborate  of  sodium  mixed  with 
saHva  on  a  tooth,  and  found  that  there  was  no  erosive  action 
that  could  be  detected  by  the  Brown  &  Sharpe  micrometer. 
This  was  particularly  gratifying,  as  perborate  of  sodium  is  a 
bland  salt  that  can  be  freely  placed  in  the  mouth  without  caustic 
action;  it  liberates  9  to  10  per  cent,  of  oxygen,  and  in  the  presence 
of  any  acid  that  may  be  present  forms  a  strong  alkaline  peroxid 
solution. 

Therefore,  when  there  are  any  grooves  on  the  front  teeth  the 
author  forbids  the  use  of  grit  dentifrices  and  recommends  the 
use  of  perborate  of  soda  alone;  and  when  patients  have  been 
carefully  instructed  in  the  proper  way  of  brushing  their  teeth, 
perborate  of  soda  seems  quite  able  to  keep  the  teeth  clean.  For 
patients  that  have  healthy  gums,  with  no  tendency  to  gum  re- 
cession or  thinning  of  the  enamel,  the  following  formula  may 
be  used: 

Peroxid  of  magnesium  (sieve  200  fine) 60  parts. 

Perborate  of  sodium 30      " 

Pulv.  saponis. 10      " 

Flavoring  to  suit. 

When  an  extracted  tooth  was  brushed  for  ten  minutes  with 
this  powder  no  loss  of  enamel  occurred  and  a  barely  measurable 
loss  of  cementum. 

Three  specimens  of  chalk  were  also  tested :  The  first  sample 
was  made  by  precipitation  in  50  liters  of  water  with  slow  precipita- 
tion. The  second  was  made  by  quick  precipitation  in  a  strongly 
concentrated  solution.  The  slow  precipitate,  as  would  be  ex- 
pected, gave  a  larger  crystal  than  the  quick  precipitate.  The 
larger  crystals  of  the  first  specimen  varied  from  17  to  5.6  microns 


A   STUDY   OF   TOOTH   ENAMEL  AND    SALIVA  63 

in  diameter;  the  smaller  crystals  of  the  second  specimen  meas- 
ured from  4  to  2  microns  in  diameter.  The  third  specimen  was 
composed  of  precipitated  chalk  very  finely  ground,  and  yet 
these  three  specimens  seemed  about  equally  destructive  of 
enamel  and  cementum.  This  would  indicate  that  it  is  the  chalk 
itself,  not  the  preparation,  that  is  responsible  for  its  destructive 
action. 

Specimens  of  silicious  earth,  precipitated  phosphate  of  cal- 
cium, precipitated  carbonate  of  calcium,  and  calcined  magnesium 
(light)  were  tested  for  their  erosive  action,  as  the  table  of  tests 
will  show.  In  these  erosion  tests  a  tooth-brush  charged  with 
saliva  and  various  grits  was  swept  by  hand  over  a  natural  tooth 
for  ten  minutes.  Saliva  from  the  same  mouth  was  used  through- 
out all  the  tests: 

Number  of      Loss  of  enamel    Loss  of  cementum 

minutes.           o.oooi  inch.  o.oooi  inch. 

Dentifrice  i 10  i  26 

Dentifrice  2 10  i  83 

Dentifrice  3 10  o  66 

Dentifrice  4 10  a  trace  121 

Dentifrice  5 10  o  73 

Dentifrice  6 10  o  7 

Dentifrice,  Dr.  X 10  i  ^^ 

Dentifrice,  Dr.  Head  (old  formula) 10  i  20 

Various  kinds  of  precipitated  chalk 10  1-3  8-18-28 

Magnesium  carbonate  (precipitated) 10  o  19 

Precipitated  calcium  phosphate 10  i  36 

Tooth  brushed  with  saliva  alone 10  o  o 

Magnesia,  calcined 10  1-3  27 

Perborate  of  soda 10  o  o 

Dr.  Head's  new  formula 10  o  3-9 

Very  fine  peroxid  of  magnesia 10  o  o 

Saturated  solution  of  sodimn  silicofluorid.  . .  10  o  o 

Hexamethylenamin 10  i  i 

Summary.— In  closing  this  chapter  let  us  briefly  go  over 
some  of  the  points  that  might  properly  be  emphasized.  Tooth- 
powders  containing  grits  are  harmful  to  both  enamel  and  ce- 
mentum, and  the  patients  should  be  taught  to  brush  and  cleanse 
the  teeth  without  their  aid.  AU  stains  that  cannot  be  removed 
without  the  aid  of  tooth-cutting  grit  should  be  removed  only 
by  the  dentist.     Moreover,  the  patient  should  be  trained  so 


64  MODERN  DENTISTRY 

thoroughly  in  the  use  of  the  brush  and  floss-silk  that  dentifrices 
and  mouth-washes  will  be  of  minor  importance.  Very  finely 
powdered  peroxid  of  magnesium,  with  lo  per  cent,  of  soap  and 
a  suitable  flavoring  agent,  makes  a  valuable  antiseptic  peroxid 
powder,  and  when  left  around  the  teeth  at  night  it  will  prove  an 
invaluable  antacid.  For  those  who  do  not  wish  a  semblance  of 
grit  in  their  powder,  flavored  perborate  of  soda  can  be  used 
both  on  the  brush  and  also,  in  lo-grain  tablet  form,  as  valuable 
mouth-wash  tablets. 

A  I  per  cent,  peroxid  of  hydrogen  wash  held  in  the  mouth  for 
two  or  more  minutes  will  reduce  inflammation  rapidly  and  quickly. 
A  saturated  solution  in  water  of  sodium  sihcofluorid  is  also  ordi- 
narily useful.  It  forms  a  0.61  per  cent  solution.  This  may  be 
held  in  the  mouth  from  two  to  five  minutes,  three  times  a  day, 
by  patients  under  treatment  for  pyorrhea.  While  in  some  few 
cases  it  causes  a  brown  precipitate  on  the  teeth  which,  however, 
is  easily  removable,  in  every  case  its  healing  effect  on  the  inflamed 
gums  is  so  satisfactory  as  to  be  little  less  than  marvelous.  It  is 
non-poisonous  and  cheap,  being  readily  purchased  c.  p.  at  75 
cents  a  pound,  which  is  enough  to  make  almost  a  barrel  of 
mouth-wash.  And,  above  all,  being  a  fluorid,  it  has  the  fluorid 
antiseptic  qualities  without  the  usual  resultant  erosive  action 
on  the  procelain  crowns  or  fillings. 


CHAPTER  IV 

TREATMENT  OF  MOUTH  INFECTION 

General  Diagnosis.^ — In  determining  the  causes  of  mouth 
infection  it  is  of  utmost  importance  that  a  comprehensive  study- 
should  be  made  of  the  entire  body  to  determine  the  presence 
of  associated  disease.  And  here  is  where  the  sympathetic, 
scientific  co-operation  between  the  general  practitioner  and  the 
dentist  is  of  the  utmost  importance.  Purely  local  infections  can 
be  treated  and  cured  by  local  treatment,  but  where  the  mouth 
infection  has  spread  to  other  organs  of  the  body,  such  as  the 
stomach,  intestines,  genito-urinary  tract,  etc.,  secondary  infection 
occurs  which  weakens  the  bacterial  resistance  of  the  blood  and 
causes  the  original  infection  to  reappear  in  the  mouth,  even 
though  it  had  temporarily  yielded  to  local  treatment.  Normal 
blood  has  a  certain  germicidal  power  that  will  ordinarily  resist 
bacterial  invasion.  But  if  the  bacterial  invasion  becomes 
intrenched  both  in  position  and  number,  and  lowers  the  resistance 
of  the  blood,  it  is  evident  that  the  first  step  in  the  restoration  of 
the  blood  to  its  normal  germicidal  power  is  to  first  remove  the 
depot  of  infection  that  is  the  primary  cause  of  blood  poverty. 

The  mouth  has  long  been  considered  a  sort  of  health  ba- 
rometer of  the  general  body.  It  is  now  recognized  not  only  as 
a  gage  of  the  general  systemic  health,  but  also  as  one  of  the 
principal  sources  of  primary  infection  that  may  spread  general 
disease.  This,  by  reacting  on  the  body  vigor,  may  increase 
the  mouth  infection,  which  will,  by  its  increased  reaction,  cause 
a  still  greater  lowering  of  the  general  vitahty.  In  fact,  mouth 
infection  in  its  relation  to  the  whole  body  might  be  likened  to 
a  vicious  poHtical  gang  in  its  relation  to  the  state.  The  gang 
captures  the  city  organization  through  weakness  or  sluggishness 
on  the  part  of  the  voters,  just  as  the  infection  makes  its  first  in- 

5  65 


66  MODERN  DENTISTRY 

road  into  the  tissues.  Being  intrenched  in  the  city  government, 
the  gang  poisons  the  minds  and  lowers  the  moral  resistance 
of  influential  citizens  by  concessions  and  special  privileges 
that  make  them  dependent  on  the  gang  for  their  subsistence. 
Similarly,  the  once  healthy  tissues  finally  endure  bacterial  in- 
vasion in  the  form  of  chronic  infection,  which  from  that  time 
on  pours  its  toxins  into  the  blood  stream,  causing  degeneration 
of  the  vital  organs,  any  one  of  which  may  then  become  a  new 
depot  of  infection,  sending  out  poisons  that  strengthen  the  power 
and  position  of  the  original  bacterial  gangsters.  And  just  as  at 
the  start  the  ehmination  of  the  original  infection  or  gang  would 
have  prevented  the  general  infection,  so  when  the  infection 
becomes  general  and  is  composed  of  a  number  of  individual 
gangs  or  depots  of  infection,  every  one  of  these  infecting  depots 
must  be  removed  before  the  body  or  state  can  be  considered 
sound,  for  each  one  of  the  depots  can  spread  and  become  general 
I'ust  as  the  first  depot  of  infection  spread. 

Thus,  mouth  infection  cannot  be  considered  from  a  purely 
local  point  of  view,  but  must  be  treated  both  as  a  symptom  and 
a  cause.  Where  it  is  pronounced,  and  the  teeth  and  gums  show 
general  advanced  deterioration,  the  general  practitioner  should 
go  over  the  heart,  lungs,  liver,  spleen,  kidneys,  etc.,  with  special 
care,  and  the  general  body  weight  should  be  carefully  noted. 
In  fact,  no  means  of  investigating  the  body  for  depots  of  infection 
should  be  neglected.  Any  tuberculous,  syphilitic,  or  gonorrheal 
taint  should  be  treated  as  a  matter  of  vital  importance.  The 
eye,  ear,  nose,  throat,  and  especially  the  tonsils  should  be  ex- 
amined, and  if  found  infected,  should  all  be  treated,  thus  eliminat- 
ing them  as  possible  depots  of  infection.  This  does  not  mean 
that  ten  or  twenty  doctors  will  have  to  be  working  on  one  poor 
patient  at  the  same  time.  Ordinarily  the  co-operation  of  a 
general  practitioner  will  be  all  that  is  necessary. 

Many  physicians  are  laboring  under  the  mistaken  idea  that 
the  mere  extraction  of  infected  teeth  will  be  sufficient  to  remove 
the  full  effects  of  the  infection.  Such  extraction  will  effect  a 
cure  only  while  the  infection  is  purely  local,  but  as  the  infection 
may  have  spread  to  other  parts  of  the  body  through  bacterial 


TREATMENT  OF  MOUTH  INFECTION  67 

migration,  the  extraction  of  an  infected  tooth  may  be  as  bene- 
ficial as  locking  the  stable  door  after  the  horse  has  been  stolen. 
Such  extraction  without  a  judicious  bacterial  examination  may 
actually  do  harm,  since  it  will  take  away  the  opportunity  of 
following  the  infection  in  its  migration  through  the  body  and 
ehminating  it  by  an  autogenous  vaccine  made  from  the  original 
source  of  infection. 

The  urine  should  be  carefully  examined,  with  special  reference 
to  the  presence  of  albumin,  sugar,  casts,  and  indican.  Indican 
is  frequently  present  as  a  systemic  association  of  mouth  infec- 
tion, and  its  disappearance  is  noted  as  the  treatment  progresses 
to  a  successful  termination.  A  careful  and  complete  blood- 
count  should  always  be  made.  The  intensity  of  the  hemoglobin 
and  the  number  of  the  red  corpuscles  should  be  noted.  The 
white  blood-corpuscles  should  be  especially  observed  to  see  if 
any  leukocytosis  is  present.  The  differential  white  blood-cor- 
puscle count  should  be  also  made  with  a  view  to  seeing  whether 
there  is  any  marked  lymphocytosis,  as  this  would  caution  us 
to  look  for  inflammatory  lymphatic  enlargement  during  the 
treatment.  The  joints  should  be  examined  for  gouty  deposits 
and  crepitation.  This  especially  applies  to  the  knee-joints. 
The  glands  of  the  axillae  and  neck  should  be  examined  for  enlarge- 
ment. In  a  woman  the  breasts  should  be  examined  for  hard 
lumps  or  indurations,  as  these  will  have  a  special  lowering 
effect  upon  the  system  and  should  receive  surgical  attention, 
if  necessary.  In  fact,  a  dentist  in  treating  mouth  infection  is 
like  a  countryman  at  a  fair  who  buys  a  pair  of  gloves  with  the 
privilege  of  taking  a  grab  in  the  grab-bag.  The  dentist  knows 
he  is  going  to  treat  and  probably  cure  the  mouth  infection,  but 
he  does  not  know  what  other  disease  he  is  going  to  unearth  and 
cure  with  the  aid  of  the  general  practitioner.  It  therefore  is 
wise  to  have  a  general  diagnosis  made  on  as  broad  Hnes  as  possible, 
so  as  to  note  the  general  systemic  improvement  as  the  mouth 
infection  disappears,  and  to  make  it  possible  to  give  a  more  ac- 
curate promise  in  regard  to  the  permanence  of  the  cure. 

Local  Diagnosis. — Having  laid  down  in  a  general  way  the 
lines  of  investigation  that  should  be  followed  in  the  physical 


68  MODERN  DENTISTRY 

examination  and  the  laboratory,  let  us  discuss  what  measures 
should  be  taken  in  the  local  diagnosis  of  the  disease  in  the  mouth. 
All  inflamed  spots  should  be  noted  and  each  tooth  should  be  tested 
between  the  fingers  for  looseness.  Then  a  fine  probe  should 
be  passed  around  the  necks  of  all  the  teeth,  searching  for  pockets 
of  infection,  for  these  are  not  by  any  means  always  associated 
with  redness  or  inflammation.  Where  there  is  an  old  chronic 
infection  around  a  root  there  may  be  no  redness  or  soreness. 
In  an  adult,  where  the  instrument  goes  under  the  gum  for  a  dis- 
tance of  I  inch,  peridental  deterioration  is  indicated;  and  where 
the  probe  will  penetrate  between  the  root  and  the  bony  socket 
for  I  inch  or  more  a  pyorrhea  pocket  of  infection  is  surely 
present  and  should  be  so  considered  and  treated.  When  the 
pocket  of  infection  extends  so  far  along  the  root  as  to  approach 
the  tip,  it  must  not  be  forgotten  that  the  pulp  within  the  tooth 
has  undoubtedly  become  infected  and  that  the  pocket  cannot 
be  healed  until  the  pulp  within  the  tooth  has  been  removed,  and 
the  nerve  canal  or  canals  sterilized  and  filled  antiseptically. 
Special  care  should  be  given  to  the  spaces  between  the  teeth,  as 
the  pockets  of  infection  usually  start  in  such  places. 

Having  carefully  examined  the  gums  for  pockets  and  open 
fistulse,  the  condition  of  the  pulps  of  the  teeth  should  next  be 
investigated,  because  a  living  pulp  infected  either  by  a  cavity  of 
decay,  filled  or  unfilled,  or  by  gum  infection  along  the  root,  may 
be  a  serious  depot  of  general  infection.  As  before  stated,  an 
infected  living  pulp  will  hinder  if  not  prevent  the  healing  of  the 
inflamed  gum  around  it,  so  long  as  it  is  in  a  position  to  pour  out 
its  insidious  stream  of  infection  through  the  tip  of  the  root. 
Infected  pulps  are  either  oversensitive  or  undersensitive  to  the 
apphcation  of  heat.  If  the  infection  has,  as  one  might  say, 
exasperated  an  inflamed  tissue,  the  tooth  will  be  excessively 
sensitive  to  heat  to  such  an  extent  as  to  cause  a  flash  of  pain  that 
will  extend  over  the  entire  side  of  the  face.  If,  however,  the 
infection  has  progressed  so  far  that  the  pulp  is  d3dng  or  nearly 
dead,  heat  will  cause  Httle  or  no  reaction.  The  instrument  for 
such  diagnosis  consists  of  an  electric  cautery  heated  to  the 
point   of  just   turning   paper   black    (Fig.    25).     This   electric 


TREATMENT  OF  MOUTH  INFECTION  69 

cautery  can  be  kept  at  an  even  temperature  and,  therefore, 
the  same  amount  of  stimulation  will  follow  its  application  to  the 
teeth  during  a  given  period.  Thus  the  relative  irritabihty  of 
the  pulps  can  be  readily  ascertained,  which  palpably  would 
not  be  possible  with  a  steel  instrument  heated  in  the  gas  flame. 
Having,  then,  heated  the  electric  cautery  just  to  the  point  of 
turning  paper  black,  it  should  be  applied  to  the  neck  of  each  tooth 
for  a  second  at  a  time.  If  the  consequent  pain  immediately 
disappears,  the  pulp  is  probably  normal,  but  if  the  pain  does  not 
disappear  for  three  or  four  seconds,  infection  of  the  pulp  is 
indicated;  and  if  a  flash  of  pain  extends  over  the  face,  causing  a 
lasting  neuralgic  thrill,  the  pulp  is  seriously  infected  and  should 


Fig.  25. — Electric  cautery  used  in  diagnosing  the  condition  of  the  dental  pulp. 

(Cut  f  actual  size.) 

be  removed  at  once.  Where  no  reaction  at  all  is  obtained  and 
the  tooth  shows  no  signs  of  the  pulp  having  been  removed  and 
the  canals  previously  filled,  the  tooth  should  unquestionably 
be  opened  and  the  canals  sterilized  and  filled,  because  clinical 
experience  has  proved  that  in  such  a  case  the  pulp  is  usually 
dead  and  putrescent  and  may  be  the  cause  at  any  time  of  \dolent 
organic  infection.  Teeth  with  dead  pulps  may  be  associated 
with  pain  during  the  process  of  mastication  or  may  be  especially 
sensitive  to  a  sharp  rap  on  the  masticating  surface,  a  condition 
which  exists  when  the  irritating  infection  is  acute.  But  when  in 
the  course  of  time  the  inflammation  has  become  chronic,  the  tooth 
may  appear  almost  normal  and  the  electric  cautery  is  the  best 
diagnostic  instrument  for  detecting  the  true  condition  by 
demonstrating  an  absence  of  response  to  heat.     It  must,  however, 


70  MODERN  DENTISTRY 

be  remembered  that  some  teeth  are  normally  insensitive  to  heat, 
while  others  are  supersensitive,  this  being  a  systemic  condition 
of  the  nerves  in  general.  Therefore,  variations  from  the  normal 
response  should  be  regarded  as  significant  of  possible  pathologic 
irritation  and  infection.  It  also  must  be  remembered  that  the 
molars  ordinarily  respond  to  changes  of  temperature  much  less 
than  central  incisors  or  canines,  owing  to  the  difference  in  the 
amount  of  tooth  structure  the  heat  has  to  travel  before  reaching 
the  pulp.  Therefore  if  a  molar  and  canine  respond  equally 
under  stimulation,  it  will  indicate  that  the  molar  is  oversensitive 
or  the  canine  less  sensitive  than  normal.  When  a  general  lack 
of  response  to  heat  is  noted,  unaccompanied  by  inflammation 
in  the  gums  surrounding  the  teeth,  we  should  always  bear  in 
mind  that  this  may  be  due  to  a  normal  atrophy  of  the  pulps, 
unaccompanied  by  infection.     In  such  a  case,  unless  there  is 


Fig.  26. — Automatic  hammer,  formerly  used  for  inserting  gold  fillings,  now  most 
effective  in  testing  relative  sensibility  of  teeth  to  the  force  of  percussion. 

a  systemic  depression  indicating  a  masked  depot  of  infection,  such 
teeth  should  be  left  undisturbed.  If,  however,  applications  of 
the  cautery  cause  an  extraordinary  flash  of  pain  in  any  one  tooth, 
lasting  for  several  seconds,  the  pulp  should  be  removed  and  the 
canals  filled.  The  instrument  for  testing  sensibility  under  per- 
cussion is  the  automatic  hammer  that  will  give  a  blow  of  from 
4  to  6  pounds  (Fig.  26).  The  old  plugger  used  for  malleting  gold 
will  serve  this  purpose  admirably.  Each  tooth  should  be  tested 
with  this  hammer  on  the  grinding  surface  for  sensibility  at  the 
tips  of  the  roots,  for,  as  just  stated,  where  infection  has  been  forced 
into  the  gums,  such  a  blow  will  be  associated  with  much  pain  un- 
less the  inflammation  has  become  chronic.  It  is  astonishing  how 
these  tests  for  excessive  mobility,  exploration  for  pockets  and 
fistulte,  reaction  to  heat,  and  reaction  to  a  blow  or  pressure  will 
corroborate  one  another.  Where  a  tooth  shows  excessive 
mobility,  and  the  pulp  is  infected  to  the  point  of  inflammation, 


TREATMENT  OF  MOUTH  INFECTION 


71 


there  will  be  a  sharp  reaction  to  heat,  and  usually  it  will  be  as- 
sociated with  a  pus  pocket  in  the  gum,  and  frequently  will  be 
sore  to  pressure.  Also  where  there  is  excessive  mobility  the 
tooth  may  or  may  not  be  associated  with  a  pus  pocket,  there 
may  be  no  reaction  to  heat,  and  it  may  or  may  not  be  sensitive 
to  pressure,  showing  a  state  of  more  or  less  chronic  infection  that 
is  none  the  less  dangerous  because  it  is  masked. 


Fig.  27. — Dry-cell  battery,  supplied  with  a  milliammeter,  used  in  diagnosis  and 
treatment  of  blind  abscesses.     Various  terminals  are  shown. 


Electrolysis  Test. — There  is  another  test  that  is  occasionally 
valuable  in  diagnosing  the  presence  of  a  blind  abscess  under  the 
gum,  namely,  the  ionization  test  with  the  direct  current  of  an 
electric  battery  (Fig.  27).  The  direct  current  of  a  series  of  dry 
cells  is  used.  The  positive  pole  is  placed  in  the  hand  of  the  patient 
in  the  form  of  a  large  wet  sponge.  The  negative  pole,  in  the  form 
of  a  small  German-silver  electrode,  the  sides  protected  by  rubber. 


72  MODERN  DENTISTRY 

is  then  swept  back  and  forth  over  the  infected  areas,  with  the 
current  turned  on  until  it  reaches  i  or  i|  milHamperes. 

Four  or  five  dry  cells  are  usually  enough  to  give  such  a  current, 
but  it  is  better  to  have  i6  in  all,  to  allow  for  deterioration. 
When  the  negative  pole  has  been  swept  across  the  gum  for  a 
minute  or  so,  a  white  froth  begins  to  come  through  the  gum,  that 
looks  something  like  pus,  but  is  not  pus  as  it  can  be  obtained 
from  healthy  tissue  as  well  as  from  inflamed  tissue,  the  only 
difference  being  that  in  healthy  tissue  a  stronger  current  is  re- 
quired. This  froth  can  come  through  the  gum  without  causing 
any  wound  or  erosion,  and  its  extraction  from  an  inflamed  gum 
has  special  therapeutic  value.  When  i^  to  i  dram  of  this  frothy 
serum  has  been  obtained  the  pain  and  irritation  of  the  tissue 
treated  will  disappear  in  a  manner  almost  magical,  and  in  a  day 
or  two  the  tissue  will  usually  be  found  to  have  healed.  This 
instrument  skilfully  used  for  an  hour  or  more  will  even  abort 
an  acute  alveolar  abscess.  As  a  test  for  the  presence  of  a  blind 
fistula  the  negative  pole  is  swept  over  the  inflamed  tissue  and  the 
frothy  serum  is  extracted  as  previously  described.  If  there  is  a 
blind  fistula  near  the  surface,  a  red  spot  will  suddenly  appear  on 
the  gum  and  the  fistula  will  be  actually  drawn  to  the  surface. 
The  rest  of  the  gum  region  being  wiped  dry  will  appear  unchanged, 
except  that  it  will  be  less  inflamed  and  engorged. 

A  possible  though  probably  incomplete  explanation  of  this 
phenomenon  is  as  follows:  The  large  positive  pole  distributes 
and  weakens  the  intensity  of  the  current  to  such  an  extent  that 
there  is  practically  no  local  therapeutic  action.  But  the  current 
at  the  negative  pole  is  concentrated,  and  there  the  blood-serum 
is  broken  up  by  the  ionization  into  the  positive  and  negative 
ions — since  the  positive  pole  of  a  battery  attracts  the  negative 
ions,  and  the  negative  pole,  the  positive  ions.  The  negative  pole 
of  the  battery  extracts  these  positive  ions,  leaving  the  negative 
ions  free  within  the  tissues.  A  large  proportion  of  the  substance 
of  the  blood-serum  is  water,  which  is  composed  of  hydrogen 
(positive)  and  oxygen  (negative),  and  thus  the  negative  pole 
in  extracting  frothy  serum  most  probably  extracts  the  positive 
hydrogen  from  the  water  of  the  serum  and  leaves  within  the  tis- 


TREATMENT  OF   MOUTH   INFECTION  73 

sues  nascent  oxygen  which  has  long  been  recognized  as  a  powerful 
germicide  and  stimulator  of  cell  growth.  Just  how  the  oxygen 
stimulates  the  cell  growth  or  acts  as  a  germicide  may  not  be 
quite  clear,  but  just  as  we  know  that  it  is  necessary  for  the  oxygen 
entering  the  lungs  to  permeate  all  the  tissues  of  the  body,  if  the 
body  is  to  develop  and  grow,  so  it  is  not  unreasonable  to  suppose 
that  by  the  electric  battery  appKed  in  this  manner  we  have  made 
a  sort  of  local  respiration  and  have  produced  locally  on  tissues 
of  reduced  vitality  the  same  stimulation  that  the  oxygen  from  the 
lungs  is  producing  generally  throughout  the  body.  This  theory 
does  not  take  into  account  the  possibly  important  action  of 
the  other  negative  ions  that  are  set  free  with  the  oxygen,  the  action 
of  which  may  also  have  great  therapeutic  value. 

So,  basing  the  theory  of  this  therapeutic  phenomenon  on  the 
stimulating  action  of  nascent  oxygen  set  free  in  the  tissues, 
which  theory  is  admittedly  incomplete,  the  following  would  be 
a  possible  explanation:  Inflammatory  gum  tissue  contains  more 
fluid  than  the  normal  tissue,  and  therefore  is  perhaps  a  better 
conductor  of  electricity.  Where  there  is  the  greatest  current 
there  will  naturally  be  the  greatest  cell  disintegration,  and  there- 
fore where  there  is  a  blind  abscess  hidden  under  the  gum  there 
will  be  a  natural  path  for  the  electric  current  which  will  con- 
centrate on  that  spot  and  break  down  the  overlying  tissues  so 
as  to  reveal  the  path  of  the  fistula  hidden  beneath.  When  this 
hidden  fistula  is  revealed,  it  can  be  opened  and  treated  sur- 
gically. The  x-ray  photograph,  as  will  be  shown  later,  is  a 
valuable  guide  in  diagnosing  the  conditions  of  the  hard  tissues, 
but  it  gives  very  little  idea  of  the  inflammatory  state  of  the  soft 
tissues  covering  the  bone,  and  this  ionization  test  will  frequently 
reveal  conditions  hidden  beneath  the  mucous  membrane  that 
could  be  revealed  in  no  other  way. 

This  therapeutic  phenomenon,  as  shown  by  the  direct  electric 
current,  was  brought  to  the  attention  of  a  dental  society  some 
fifteen  years  ago  by  a  man  who  claimed  that  he  could  cure  a  boil 
by  the  application  of  the  current  as  just  described.  He  even 
claimed  that  he  could  draw  pus  from  a  boil  on  one  arm  through 
the  body  and  out  on  the  other  arm.     This  preposterous  claim 


74  MODERN  DENTISTRY 

caused  him,  metaphorically,  to  be  laughed  out  of  court,  and  he 
made  very  little  impression  by  his  statements.  However,  there 
were  a  few  who  were  impressed  by  his  evident  sincerity,  and  they 
found  that  while  his  explanation  was  wrong,  and  that  he  did  not 
extract  pus,  as  he  claimed,  nevertheless  his  method  did  reduce 
inflammation  in  an  extraordinary  degree.  It  is  a  matter  of  fact, 
however,  that  this  method  as  just  described  has  been  successfully 
appHed  to  the  cure  of  inflammatory  tissue. 

The  violet-ray  apparatus  (Fig.  28)  is  also  a  great  aid  in  the 
diagnosis  of  the  condition  of  the  pulp  within  a  tooth.  The  current 
should  be  turned  on  until  the  spark  will  jump  about  |  inch  from 
the  electrode  to  the  finger  held  near  it  as  a  test.  The  electrode 
should  then  be  placed  upon  the  cutting  edge  or  grinding  surface 


Fig.  28. — Violet-ray  apparatus. 

of  the  tooth  to  be  tested.  An  interrupted  current  should  then 
be  thrown  on  the  tooth.  This  can  be  easily  done  by  the  operator 
tapping  the  electrode  with  his  finger.  If  the  pulp  is  inflamed, 
there  will  be  an  intense  response;  if  the  pulp  is  slightly  alive, 
there  may  be  a  response  that  would  hardly  be  obtained  by  the 
cautery;  and  if  there  is  no  response  at  all,  it  is  wise  not  to  be  too 
sure  that  the  pulp  is  dead  unless  these  tests  are  corroborated 
by  others.  Unbroken  tooth  enamel  sometimes  offers  complete 
resistance  to  the  violet-ray,  but  the  exposed  dentin  ordinarily 
accepts  it  readily.  This  test  should  always  be  used  as  a  check  to 
the  cautery  test,  which  it  supplements  in  an  interesting  w^ay. 
Sometimes  the  application  of  the  violet-ray  will  cause  an  active 
stimulation  to  a  tooth  where  the  pulp  is  dead  and  a  blind  abscess 


TREATMENT   OF   MOUTH   INFECTION  75 

has  formed  at  the  tip  of  the  root.  This  may  be  due  to  pressure 
occasioned  by  liberation  of  gases  from  the  fluids  in  the  bony 
cavity  beyond  the  apical  foramen.  The  application  of  the  violet- 
ray  is  also  an  excellent  means  of  reducing  general  inflammation 
of  the  mouth. 

And  last,  and  one  of  the  most  important  means  of  diagnosis, 
is  the  x-isiy,  which  will  be  dwelt  upon  at  length  in  Chapter  XII. 

Local  Treatment. — Having  seen  that  the  patient  receives  a 
thorough  general  treatment  in  order  that  the  depots  of  infection 
may  be  removed  from  other  parts  of  the  body  than  the  mouth, 
it  is  then  most  essential  that  the  dentist  should  see  that  no  foci  of 
infection  should  be  overlooked  in  the  region  over  which  he  has 
particular  control.  Every  crown  should  be  examined  as  a  possible 
depot  of  infection ;  if  the  edges  project  into  the  gums  and  cannot 
be  smoothed  so  as  to  be  non-irritating  to  the  surrounding  tissues, 
the  crown  should  be  removed  and  replaced  by  one  that  will  not 
be  a  depot  of  infection.  In  fact,  one  of  the  easiest  ways  of  tighten- 
ing a  loose  root  is  ordinarily  to  remove  a  badly  fitting  crown. 
This  one  act  is  frequently  all  that  is  necessary  to  effect  a  cure. 
After  the  crown  has  been  removed  the  inside  of  the  root  or  tooth 
should  be  carefully  tested  for  infection  within  the  canal.  If  the 
pulp  is  alive,  it  should  be  tested  with  the  cautery  or  violet-ray 
electrode  to  see  if  it  is  sound,  but  as  it  usually  happens  in  such 
cases  that  the  pulp  is  diseased  or  dead,  the  canal  or  canals  should 
be  opened  and  properly  cleansed  and  fiUed.  And  here  it  can  be 
stated  that  if  there  is  no  fistula,  open  or  blind,  at  the  end  of  a  root 
that  has  been  properly  fiUed,  and  if  there  is  no  pocket  around  such 
a  tooth,  that  tooth  or  root  can  be  excluded  absolutely  as  a  source 
of  infection,  and  attention  can  confidently  be  turned  to  other 
portions  of  the  mouth.  It  is  weU  to  emphasize  this  fact,  since 
many  good  serviceable  roots  and  teeth  have  been  ruthlessly 
extracted  at  the  order  of  the  medical  profession  in  a  desire  to 
get  rid  of  mouth  infection;  and  while  it  is  no  doubt  better  that 
five  good  teeth  should  be  extracted  rather  than  that  one  depot 
of  infection  should  remain  in  the  mouth  of  a  patient,  it  is  never- 
theless unfortunate  that  any  good  teeth  should  be  sacrificed  for 
the  lack  of  proper  scientific  diagnosis  and  treatment. 


76  MODERN  DENTISTRY 

But  to  continue  in  our  surgical  treatment  of  mouth  infection. 
What  was  said  of  crowns  appKes  even  more  to  bridges  that  can- 
not be  cleansed  between  the  bridge  and  the  gums,  and  especially 
around  the  supporting  roots.  No  bridge  should  be  inserted  in 
the  m.outh  that  cannot  be  kept  clean  as  the  natural  teeth,  and 
where  this  is  impossible,  and  where  the  bands  of  the  supporting 
crowns  project  into  the  gums,  forming  ledges  for  infection,  the 
bridges  should  be  removed  and  the  supporting  abutments 
investigated,  and,  if  necessary,  treated.  The  non-cleansable 
bridge  should  be  replaced  by  a  bridge  that  is  natural  in  appear- 
ance, effective  for  mastication,  and  capable  of  being  cleansed  as 
thoroughly  as  any  of  the  natural  teeth. 

Next,  every  tooth  should  be  examined  for  cavities  of  decay, 
and  all  the  fillings  in  the  teeth  should  be  carefully  examined  for 
.recurrence  of  decay.  When  a  cavity  of  decay  is  found  or  re- 
current decay  is  discovered  under  a  filHng,  all  of  the  decayed 
material  should  be  thoroughly  removed,  and  if  the  pulp  is  thereby 
exposed,  it  should  be  anesthetized  and  removed,  for  it  is  incon- 
ceivable that  decay  could  reach  the  pulp  without  seriously  in- 
fecting it.  It  is  true  that  such  an  exposed  pulp  may  be  capped 
and  preserved  in  a  Hving  state  for  years,  but  ordinarily  the 
extreme  sensibihty  of  the  tooth  to  thermal  change  or  the  steady 
decrease  in  normal  sensibility  marks  it  as  a  source  of  possible 
if  not  probable  infection  to  the  system  at  large.  As  long  as  in- 
fection was  not  recognized  as  a  source  of  systemic  danger,  the 
preservation,  by  capping,  of  a  pulp  exposed  by  decay  was  de- 
fensible, but  in  the  Hght  of  our  newer  knowledge,  it  is  indefen- 
sible, and  the  time  is  not  far  distant  when  it  will  be  called  mal- 
practice, for  the  pulp  of  a  thoroughly  developed  tooth  is  not 
essential  to  its  vitality,  appearance,  or  functions.  The  pulp  is 
the  organ  that  forms  the  tooth-bone  during  its  formative  period, 
but  that  period  being  over,  it  is  exceedingly  prone  to  deterioration 
and  infection.  The  real  nourishment  and  maintenance  of  a  tooth 
come  from  the  membrane  supporting  it  in  the  tooth  socket,  and 
as  long  as  this  membrane  is  healthy  and  free  from  infection  there 
is  no  fear  but  that  the  tooth  will  be  able  to  perform  all  of  its 
proper  functions.    It  is  commonly  believed  that  teeth  deprived 


TREATMENT  OF  MOUTH  INFECTION  77 

of  their  pulps  discolor.  This  is  not  necessarily  so  if  the  pulp  is 
thoroughly  and  antiseptically  removed.  Discolorations  of  the 
teeth  arise  from  putrefaction  of  the  pulp  within  the  tooth,  which 
becomes  infiltrated  with  decaying  matter.  After  the  living  pulp 
has  been  removed  the  appUcation  of  a  4  per  cent,  formaldehyd 
solution  or  any  good  albumin  coagulant  will  prevent  the  breaking 
down  of  the  albumin  of  the  tooth,  and  with  proper  filhng  of  the 
canal  no  discoloration  need  be  apprehended.  When  the  decayed 
spots  in  the  teeth  have  been  cut  out  and  filled,  the  infected 
pulps  removed,  and  the  infected  canals  sterilized  and  properly 
filled,  the  dentist  must  not  forget  to  examine  the  necks  of  the 
teeth  for  filHngs  with  overhanging  edges  that  may  collect  masses 
of  infection.  Any  such  overhanging  edges  should  be  carefully 
smoothed  and  polished  with  fissure  burs,  pohshed  until  the 
necks  of  the  teeth  are  beyond  suspicion  as  collectors  of  bacterial 
colonies.  Next,  the  interdental  spaces  should  be  carefully  ex- 
amined to  see  if  the  approximation  of  the  adjacent  teeth  is  suflEi- 
ciently  accurate  to  prevent  the  food  from  being  jammed  down 
on  the  gum  between  them  during  mastication.  Such  jamming 
spikes  the  delicate  gum  on  the  underlying  point  of  bone  that 
Hes  between  the  teeth,  and  so  starts  an  infection  that,  unre- 
strained, will  result  in  a  pus-pocket  along  the  sides  of  the  root. 
Restoration  of  the  proper  approximation  of  the  sides  of  the  teeth 
is  one  of  the  prime  means  of  curing  invading  infections  of  the 
gums  between  the  teeth. 

It  is  also  important  to  restore  the  normal  occlusion  of  the 
teeth.  When  a  tooth  has  become  inflamed  in  its  socket,  the 
peridental  membrane  is  apt  to  acquire  a  chronic  thickening  that 
raises  the  tooth  in  its  socket  and  leaves  it  permanently  higher 
than  its  neighbor.  Thus,  in  its  weakened  condition  it  has  to 
stand  the  full  force  of  mastication  that  should  be  borne  by  all 
the  teeth  on  that  side  of  the  face.  The  jaw  can  ordinarily  develop 
150  to  300  pounds  pressure  in  the  mastication  of  food,  and  this 
weakened  tooth  while  receiving  such  a  shock  cannot  hope  to 
regain  its  normal  tone.  It  takes  what  pressure  it  can,  and  then 
by  its  painful  protest  warns  its  owner  of  its  danger.  The  owner, 
therefore,  does  not  bite  so  hard,  but  favors  it,  and  in  so  doing 


78  MODERN  DENTISTRY 

does  not  properly  chew  his  food,  and  so  another  cause  of  sys- 
temic deterioration  is  established.  Therefore  it  is  of  primary 
importance  that  all  abnormalities  of  tooth  occlusion  should  be 
remedied,  and  if  any  tooth  projects  above  its  normal  line  it  should 
be  cut  down  with  an  engine  stone  until  the  pressure  of  masti- 
cation can  be  received  equally  by  all  the  teeth.  It  is  often  worth 
while  to  cut  a  sore  tooth  down  below  the  normal  bite  so  that  it 
can  be  given  a  complete  rest  until  it  regains  its  normal  tone. 
When  a  loose  tooth  can  be  advantageously  saved  it  should  be 
splinted  or  fastened  to  an  adjacent  firm  tooth,  so  that  the  act  of 
mastication  will  not  bruise  or  twist  it  in  the  bony  sockets  of  the 
jaw.  This  can  be  done  by  t3dng  them  firmly  to  each  other  with 
twisted  silk  twine,  until  the  loose  tooth  yields  to  treatment  and 
becomes  firm.  Loose  teeth  that  have  become  irregular  should  be 
straightened  before  they  are  tightened  by  treatment,  and  the 
straightening  can  usually  be  done  by  the  twisted  silk  that  is 

C^ 4^ 


Fig.  29. — Wire  needle,  No.  26  brass  or  gold  wire,  used  for  threading  dental  floss  in 
cleansing  the  interdental  spaces. 

splinting  the  teeth  together.  They  can  be  permanently  splinted 
together  when  desirable,  by  means  of  platinum  staples  inserted 
from  the  nerve  canal  of  one  tooth  to  the  nerve  canal  of  another, 
the  staples  being  set  down  in  the  substance  of  the  tooth  below 
the  line  of  mastication.  When  the  tying  or  stapling  is  done  care 
should  be  taken,  as  before  stated,  to  instruct  the  patient  how  to 
cleanse  the  interdental  spaces.  Under  such  conditions  this  is 
accomplished  by  the  use  of  floss-silk  threaded  between  the  teeth 
by  a  flexible  wire  needle  (Fig.  29).  The  needle  is  made  of  gold 
or  brass  wire,  No.  26  gage,  cut  off  to  a  length  of  3  or  4  inches. 
The  end  is  bent  over  with  a  pair  of  pliers  and  soldered  with  soft 
solder. 

One  of  the  prime  necessities  in  examining  a  case  of  mouth 
infection  is  a  good  series  of  a;-ray  plates.  Plates  should  be  made 
with  a  hard  tube  to  show  the  conditions  in  the  roots  of  the  teeth, 
and  other  plates  should  be  made  with  the  soft  tube  to  diff eren- 


TREATMENT   OF   MOUTH   INFECTION  79 

tiate  the  softened  areas  in  the  alveolar  process  that  the  hard  tube 
does  not  clearly  define.  This  is  especially  valuable  when  there 
is  systemic  disturbance  associated  with  nervous  depression.  In 
the  case  of  impacted  teeth  such  a  course  of  procedure  is  inval- 
uable, as  the  hard  tube  will  clearly  show  the  condition  of  the  tooth, 
while  the  soft  tube  will  give  the  condition  of  the  surrounding 
membrane  and  bony  processes.  Whenever  impacted  teeth  are 
found  the  impaction  should  be  removed.  And  when  all  of  these 
points  have  been  given  due  consideration  we  can  hope  to  treat 
the  pockets  of  infection  around  the  teeth  with  a  fair  prospect  of 
success. 

The  specific  treatment  of  mouth  infection  will  now  be  dis- 
cussed. The  pockets  should  be  carefully  explored  for  deposits 
of  tartar  usually  found  upon  the  roots  below  the  gums.  The 
removal  of  this  tartar  is  absolutely  essential  for  a  cure,  just  as  it 
is  necessary  to  remove  a  spHnter  before  the  wound  occasioned 
by  it  will  heal.  So  successful  is  this  local  treatment  when  carefully 
performed  that  many  dentists  claim  that  it  is  the  only  procedure 
necessary  for  a  cure,  unmindful  of  the  fact  that  sometimes  these 
pockets  around  the  teeth  occur  where  no  calcareous  scale  is 
discoverable.  Valuable  and  necessary  as  it  is  that  the  scale 
should  be  thoroughly  removed,  such  dentists  sometimes  burrow 
so  ruthlessly  around  the  roots  of  teeth  in  their  efforts  to  find 
tartar  that  they  do  more  harm  than  good,  since  their  well-meant 
efforts  often  result  in  ripping  away  much  good  tooth  attachment 
and  occasion  laceration  of  the  blood-vessels  at  the  tip  of  the  roots, 
causing  the  destruction  of  the  pulps  that  otherwise  might  have 
been  saved.  Thoroughness  should  always  be  commended,  but 
thoroughness  that  results  in  the  loss  of  a  tooth  that  more  gentle 
means  could  have  saved  is  certainly  ill-advised.  Sets  of  instru- 
ments have  been  devised  for  scaKng  the  roots  of  infected  teeth 
that  are  so  compUcated  and  require  such  special  knowledge  that 
their  inventors  peddle  them  around  and  persuade  dentists  to 
loan  them  patients  in  order  to  demonstrate  the  efficacy  of  their 
treatment,  and  these  patients  are  charged  large  fees  that  are 
divided  between  the  instrument  demonstrator  and  the  dentist 
providing  the  patient.    This  practice  is  certainly  unprofessional 


8o 


MODERN  DENTISTRY 


in  its  lack  of  frankness.  A  patient  has  every  right  to  know  to 
whom  he  is  paying  his  money,  and  any  indirection  on  this  subject 
is  apt  to  react  upon  the  candor  and  honesty  that  is  the  funda- 
mental basis  of  the  professional  relations  of  doctor  and  patient. 
These  dentists  in  claiming  that  local  scraping  will  cure  all  pyor- 
rhea pockets  are  obviously  wrong,  but  careful  curetting  allevi- 
ates so  large  a  proportion  of  cases  that  by  the  laity  their  claims 
seem  substantiated. 


^=^^=5 


Fig.  30. — Yunger  scalers. 


There  are  many  simple  and  effective  sets  of  instruments 
made  for  scaling  tartar.  The  Yunger  instruments  (Fig.  30) 
have  given  excellent  results,  as  also  have  the  Logan-Buckley 
instruments  (Fig.  31)  and  Smith's  (Fig.  32).  As  a  matter  of  fact, 
it  is  not  the  scalers  that  are  so  valuable  as  the  man  behind  the 
scaler. 

Tartar  Solvent. — Prior  to  1900  there  was  nothing  that  would 
soften  tartar  without  softening  the  tooth  as  well.  The  agonies, 
sometimes  useless,  that  patients  went  through  in  having  tartar 


TREATMENT  OF  MOUTH  INFECTION 


8i 


removed  from  the  roots  of  the  teeth  were  unspeakable,  and  as 
patient  and  dentist  in  this  treatment,  the  author  speaks  feeHngly. 
When,  however,  the  author  discovered,  through  a  series  of  ex- 
periments, that  a  20  per  cent,  aqueous  solution  of  hydrogen 
ammonium  fluorid  with  10  per  cent,  free  hydrofluoric  acid  would 


Fig.  31. — Logan-Buckley  scalers. 


soften  the  bond  between  the  tartar  and  tooth  without  harming 
the  tooth,  the  necessity  for  such  heroic  scraping  passed  away. 
This  mixture,  according  to  tests  made  by  Dr.  A.  P.  Kitchens, 
has  a  germicidal  strength  more  than  five  times  that  of  c.  p.  car- 
bolic acid  and,  in  addition  to  dissolving  the  tartar  bond  and 
6 


82 


MODERN  DENTISTRY 


minute  calcareous  scales,  it  also   stimulates  the  reattachment 
of  the  gum  to  the  root. 


Fig.  32. — Smith  scalers. 


The  local  treatment  of  the  infected  pockets  around  the  teeth 
is,  therefore,  as  follows:  The  obvious  lumps  of  tartar  should  be 
removed  without  laceration,  and  then  the  bifluorid  mixture 
should  be  gently  flowed  around  the  neck  of  each  tooth  and  into 


TREATMENT   OF   MOUTH   INFECTION 


83 


each  infected  pocket.  If  there  is  intense  inflammation  of  the 
gums,  the  solution  should  at  first  be  diluted  with  an  equal 
quantity  of  water.  In  acute  inflammation  the  first  two  or  three 
weekly  applications  of  the  undiluted  mixture  cause  intense  pain. 
After  the  diluted  mixture  has  been  applied  at  weekly  intervals 
two  or  three  times,  and  great  care  observed  in  daily  mouth  hygiene, 
the  strong  undiluted  mixture  can  be  used  with  comfort  and  ad- 


Fig.  33. — Syringe  for  application  of  bifluorid  of  ammonium  comp.  The  bulb 
is  soft  rubber,  the  barrel  celluloid,  and  the  needle  is  a  platinimi  tube  capable  of 
being  bent  in  any  direction. 


vantage,  great  care  being  taken  not  to  force  it  into  the  tissues, 
especially  into  the  young  granulations  that  are  forming  at  the 
bottom  of  the  pockets.  This  solution  should  be  applied  with  a 
platinum-pointed  syringe  with  a  celluloid  barrel  and  a  rubber 
bulb  (Fig.  33).  The  solution  vigorously  attacks  glass,  and 
therefore  such  a  syringe  as  described  must  be  used.  The  gums 
inside  and  out  should  be  protected  by  napkins  or  cotton  rolls, 


84  MODERN   DENTISTRY 

and  the  solution  gently  injected  around  the  necks  of  the  teeth 
and  within  the  pockets,  the  excess  being  wiped  off  with  a  napkin. 
The  patient  should  be  allowed  to  spit  without  rinsing  the  mouth, 
as  the  action  of  the  saliva  has  a  soothing  and  protecting  effect 
on  the  gums.  If  the  solution  is  allowed  to  dry  on  the  gums  it 
makes  a  burn  not  unlike  that  of  pure  carbolic  acid.  Where  the 
pocket  extends  along  the  tooth  deep  into  the  gums,  it  is  sometimes 
good  practice  to  pack  cotton  between  the  root  and  the  gum  and 
then  soak  it  with  the  pure  solution.  This  is  not  a  painful  pro- 
cedure if  properly  done,  and  the  next  day  the  cotton  can  be  re- 
moved, thereby  exposing  the  root  to  the  bottom  of  the  pocket, 
when  any  remaining  specks  of  tartar  can  be  readily  removed. 

The  methods  just  described  will,  in  a  majority  of  cases,  be 
sufficient  to  bring  about  a  cure  of  mouth  infection,  but  sometimes 
recovery  is  slow  or  the  general  symptoms  may  indicate  that  the 
mouth  infection  has  infected  other  portions  of  the  body  beyond 
the  reach  of  ordinary  local  surgery  or  local  therapeutic  treat- 
ment. In  such  cases  it  is  obvious  that  a  complete  cure  requires 
the  elimination  not  only  of  the  mouth  infection,  but  of  all  of  this 
same  infection  from  every  portion  of  the  body.  This  is  what 
vaccine  treatment  is  supposed  to  bring  about.  Therefore  this 
subject  will  be  treated  in  the  following  chapter. 


CHAPTER  V 

VACCINES  IN  THE  TREATMENT  OF  MOUTH  INFECTION 

Theory  of  Vaccination.— Bacterial  vaccines  are  merely  sus- 
pensions of  dead  bacteria  in  physiological  sahne  solution.  Vac- 
cination is  the  injection  of  such  suspensions  for  the  purpose 
of  stimulating  or  increasing  the  antagonistic  forces  of  the  body 
against  the  particular  species  of  bacteria  contained  in  the  vaccine. 
Just  what  these  antagonistic  forces  are  and  the  exact  manner  in 
which  they  act  have  been  subjects  of  the  most  careful  investi- 
gation ever  since  the  epoch-making  work  of  Pasteur,  scarcely 
three  decades  ago.  As  a  result,  certain  substances  or  properties 
of  the  blood-serum  in  vaccinated  persons  or  animals  have  become 
well-known  facts.  The  antagonistic  effects  of  these  newly  formed 
substances  upon  the  bacteria  have  been  demonstrated  in  test- 
tube  experiments,  and  such  reactions  naturally  suggest  to  a 
certain  degree  the  train  of  events  following  an  injection  of  bac- 
terial vaccines  into  the  tissues. 

Unfortunately,  however,  our  knowledge  is  still  incomplete; 
the  chemical  and  physical  reactions  that  take  place  within  the 
living  body  are  so  subtle  that  pure  hypothesis  must  supply  the 
connecting  links  between  the  known  and  the  unknown.  As 
new  facts  are  disclosed,  many  of  our  theories  must  be  modified 
accordingly,  sometimes  even  discarded  altogether.  Our  specu- 
lations are  merely  a  temporary  scaffolding  from  which  to  erect 
the  soKd  structure. 

Thus,  in  the  matter  of  therapeutic  inoculation,  experience 
has  taught  us  the  essential  points  in  the  method  of  injection, 
and  the  regulation  of  dosage;  experience  has  also  shown  us  the 
great  value  of  therapeutic  inoculation.  With  regard,  however, 
to  the  intimate  mechanism  by  which  these  results  are  obtained, 
the  current  explanations  offered  must  be  regarded  as  working 
hypotheses  and  nothing  more. 

85 


86  MODERN  DENTISTRY 

As  just  stated,  vaccination  consists  in  inserting  dead  disease 
germs  into  the  body  so  that  the  blood  and  tissue  cells  may  be 
stimulated  to  form  a  ferment  that  will  destroy  any  invading 
germs  of  the  same  species.  When  this  has  been  done,  two  impor- 
tant factors  against  the  growth  of  these  disease  germs  have  been 
created:  first,  the  ferment  that  will  destroy  them  is  actually 
present  in  the  blood;  second,  the  tissue  cells  have  been  impressed 
with  the  habit  of  making  this  specific  ferment  in  the  presence  of 
these  particular  micro-organisms,  so  that  in  future  if  the  tissue 
ceUs  find  themselves  adjacent  to  these  germs,  they  will  more 
readily  and  effectively  form  the  destroying  ferment. 

The  injection  of  germs  within  the  body  so  that  the  cells  may 
form  the  special  germ-destro}dng  ferment  is  called  active  im- 
munization because  it  stimulates  the  body  to  be  alert  in  its 
defence  against  the  presence  of  this  germ.  But  where  an  animal 
has  been  injected  with  disease  germs  until  its  blood  is  full  of  the 
protective  ferment,  and  this  animal's  blood  is  drawn  off  asep- 
tically  and  the  serum  refined  and  injected  into  a  patient  purely 
for  the  benefit  to  be  derived  from  the  protective  ferments  that 
are  in  the  serum,  the  procedure  is  called  passive  immunization 
because  this  immunization  does  not  create  the  habit  of  ferment 
formation  in  the  body  cells  of  the  person  injected;  it  only  pro- 
vides a  ferment  that  is  known  to  be  hostile  to  the  germs  with 
which  the  patient  is  infected.  Active  immunization  may  last 
for  years,  while  passive  immunization  gives  its  protection  for 
only  a  few  weeks  at  most. 

The  method  by  which  the  body  is  stimulated  to  destroy  and 
rid  itself  of  invading  infection  has  been  investigated  by  EhrHch, 
Metchnikoff,  Wright,  Besredka,  and  Vaughan  with  such  inspired 
research  and  such  astute  patience  that  the  basal  principles  of 
the  theory  of  immunization  seem  fairly  weU  established;  and 
while  there  are  differences  in  wording,  the  principles  enumerated 
by  each  investigator  co-ordinate  so  thoroughly  that  the  doctrine 
will  be  treated  as  a  whole,  there  not  being  sufi&cient  space  here  to 
discuss  the  special  minute  differences  of  their  individual  teachings. 

Any  protein  that  invades  the  body  parenteraUy — that  is, 
otherwise  than  through  the  normal  processes  of  the  digestive 


VACCINES  IN  THE   TREATMENT  OF   MOUTH  INFECTION         87 

tract — is  called  antigen,  whether  it  is  in  the  form  of  bacteria, 
flower-pollen,  horse-serum,  or  white  of  egg,  etc.  The  ferment 
which  destroys  this  substance  and  causes  its  elimination  is  com- 
posed of  a  combination  of  two  substances  called  co?nplement  and 
amboceptor.  Complement  is  always  present  in  the  blood  in  a  prac- 
tically fixed  amount.  The  quantity  cannot  be  markedly  increased 
by  any  known  means.  Specific  amboceptor  does  not  exist  until 
the  body  cells  are  stimulated  to  produce  it.  Its  specificity  is  a 
marked  characteristic.  It  is  active  only  against  its  correspond- 
ing antigen.  For  instance,  typhoid  bacilli  when  they  invade  the 
tissues  of  the  body  act  as  an  antigen.  They  stimulate  the  creation 
of  a  typhoid  amboceptor  that,  uniting  with  the  complement  in 
the  blood,  forms  a  ferment  which  breaks  up  the  typhoid  germ 
into  substances  that  are  readily  digestible  by  the  blood  and 
tissues.  Vaughan,  in  his  magnificent  work,  "Proteins  and  Split 
Products  in  Relation  to  Immunity  and  Disease,"  has  shown 
that  the  first  destructive  action  of  a  ferment  on  the  antigen  is 
to  split  it  into  a  poison  that  is  a  common  derivative  of  all  proteins, 
called  the  toxophore,  and  a  harmless  spUt  product  called  the 
haptophore,  solely  characteristic  of  the  particular  antigen  from 
which  it  is  derived.  For  instance,  the  toxophores  of  streptococci, 
goat-serum,  or  egg  albumin  are  all  toxicologically  the  same  poison, 
and  when  set  free  in  the  body  give  rise  to  the  same  symptoms, 
but  their  respective  haptophores,  each  non-toxic,  are  specific  of 
each  protein  from,  which  it  is  derived;  and  each  haptophore 
stimulates  by  its  presence  the  formation  of  the  particular 
amboceptor  as  an  increased  defense  against  the  invasion  of  its 
corresponding  antigen. 

Therefore,  it  is  clear  that  the  administration  of  proteins 
parenterally,  whether  serum  or  masses  of  bacteria,  whether  hving 
or  dead,  may,  under  certain  circumstances,  be  as  potent  in  their 
action  for  good  or  evil  as  strychnin  or  aconite.  By  a  beautiful 
series  of  experiments  on  animals  Vaughan  has  shown  that  ex- 
cept where  the  disease  is  caused  by  the  few  bacteria  similar  to 
the  diphtheria  and  tetanus  germs,  in  that  they  secrete  poisons 
as  they  grow,  fever  and  death  from  infectious  diseases  result 
primarily  from  the  breaking  of  protein  bacterial  masses  into 


88  MODERN  DENTISTRY 

the  toxophore  and  the  haptophore  groups.  Therefore,  if  the 
protein  substance  grows  to  a  sufficient  mass  before  the  defensive 
ferments  of  the  body  arrest  its  growth,  so  much  poison  may  be 
let  loose  upon  the  system  that  death  results.  If,  however,  the 
defensive  ferment  or  amboceptor  is  present  or  is  formed  in  suffi- 
cient quantity  to  stop  the  growth  of  the  invading  bacteria  before 
enough  protein  is  formed  to  produce  a  lethal  dose  of  the  toxo- 
phore, the  poison  is  gradually  and  continuously  destroyed  and 
the  patient  recovers.  Vaughan  has  shown  that  the  fever  of 
bacterial  disease  is  not  usually  due  to  the  growth  of  the  germs, 
but  to  their  destruction,  and  the  letting  loose  of  the  toxophore. 
He  has  also  shown  that  complete  and  effective  digestion  of  a 
protein  will  thoroughly  destroy  the  toxophore,  while  during  the 
process  the  liberated  haptophore  will  engender  in  the  tissue 
cells  a  habit  of  readiness  in  the  formation  of  the  amboceptor, 
which  thereafter  will,  whenever  it  meets  it,  destroy  the  particular 
protein  that  called  it  into  being.  After  the  formation  of  the 
amboceptor  has  ceased  and  the  need  for  it  has  passed,  there  is 
ordinarily  a  tendency  for  it  to  disappear,  the  future  defense 
being  left  to  the  educated  tissue  cells,  although  occasionally  the 
amboceptor  is  not  eliminated,  but  remains  in  large  quantities 
in  the  blood. 

Anaphylaxis. — The  storing  up  of  this  amboceptor  may  work 
for  good  or  ill,  according  to  circumstances.  If  a  certain  protein, 
say  horse-serum,  is  put  into  the  body  in  small  quantities  and  a 
large  quantity  of  amboceptor  is  formed  and  stored  up,  a  second 
dose  of  that  protein  may  result  in  death  by  the  sudden  destruc- 
tive action  of  the  amboceptor,  and  the  consequent  pouring  out 
of  the  toxophore,  that  reaches  a  lethal  dose  before  it  can  be  elimi- 
nated by  the  excretive  and  digestive  processes  of  the  body. 
Some  animals  are  much  more  prone  to  store  up  the  amboceptor 
in  a  dangerous  marmer  than  others.  The  guinea-pig  is  most 
prone  to  consistently  do  this.  In  man  this  propensity  is,  fortu- 
nately, rare.  For  instance,  if  a  guinea-pig  is  injected  with  i 
c.c.  of  horse-serum,  and  at  the  end  of  ten  to  fifteen  days 
is  injected  intravenously  with  another  cubic  centimeter  of 
horse-serum,  the  guinea-pig  will  die  of  bronchial  spasm.      If, 


VACCINES    IN    THE    TREATMENT    OF    MOU'lH    INFECTION         89 

however,  the  second  dose  consists  of  a  different  antigen,  such  as 
white  of  egg  or  goat-serum,  etc.,  the  amboceptor  present  is  not 
effective,  and  death  or  even  disturbing  symptoms  do  not  result. 
Moreover,  if  the  second  dose  of  horse-serum  is  given  in  three 
to  five  days,  the  amboceptor  has  not  formed  in  sufificient  quan- 
tity to  let  loose  a  lethal  dose  of  poison,  and  from  then  on  the 
doses  can  be  given  without  the  deadly  symptoms  that  would 
develop  if  the  second  dose  had  been  deferred  for  fifteen  days. 
This  state  of  being  hypersensitive  to  a  second  dose  is  called 
sensitization  or  anaphylaxis.  In  man  anaphylaxis  is  a  remote 
though  fatal  possibility,  and  such  a  possibility  is  always  present 
when  a  serum  is  administered  for  the  first  time  in  large  quantities. 
How  this  sensitization  occurs  is  not  known,  but  that  it  does  exist 
in  some  individuals  as  a  natural  idiosyncrasy  is  an  established 
fact,  and  possibly  fatal  consequences  can  only  be  avoided  when 
serums  are  administered  by  careful  adherence  t  o  the  precaution- 
ary routine  in  each  case.  If  a  small  trial  dose  of  a  particular 
serum,  say  0.05  c.c,  is  first  given,  and  if  at  the  end  of  an  hour  no 
itching  or  gasping  results,  the  full  dose  can  then  be  safely  admin- 
istered because  the  trial  dose  will  have  shown  that  no  ambo- 
ceptor characteristic  of  that  particular  serum  is  present.  If, 
however,  the  small  preliminary  dose  causes  these  symptoms, 
showing  that  the  ferment  is  present,  the  result  will  be  harmless, 
as  there  is  not  enough  protein  in  0.05  c.c.  to  develop  a  dangerous 
quantity  of  toxophore.  If  the  patient  is  thus  shown  to  be  sensi- 
tized, and  it  is  nevertheless  essential  that  the  serum  be  given, 
two  or  three  trial  doses  of  serum  can  be  given  at  hourly  intervals, 
so  that  the  stored  amboceptor  will  be  gradually  and  safely  ehm- 
inated,  and  then  the  full  therapeutic  dose  of  serum  can  be  admin- 
istered without  any  anaphylactic  symptoms  developing.  The 
danger  of  bronchial  spasms  or  fatal  anaphylactic  symptoms 
is  only  to  be  feared  in  the  use  of  serums,  and  with  these  only 
when  they  are  given  in  large  first  doses. 

With  vaccine  the  amount  of  protein  represented  by  the  dead 
bacteria  is  so  small  that  there  is  practically  no  danger  of  any 
anaphylactic  action  other  than  a  very  occasional  transient  rash. 
3,000,000,000  staphylococci  or  streptococci  weigh  only  i  milligram 


90  MODERN  DENTISTRY 

or  less;^  1,000,000,000  represents  the  maximum  dose  that  is  ordi- 
narily given.  Thus,  if  these  micro-organisms  were  considered 
pure  protein,  which  they  are  not  by  a  large  percentage,  a  dose 
such  as  the  3,000,000,000  bacteria  represent  would  contain 
much  less  protein  than  that  found  in  0.05  c.c.  of  horse-serum, 
which  is  the  prehminary  test  suggested  by  Vaughan  to  be  given 
to  a  patient  to  ascertain  whether  he  can  safely  take  antitoxin.^ 

The  principal  caution  to  be  observed  in  vaccine  treatment 
is  to  see  to  it  that  small  doses  are  given  at  the  start,  and  then 
cautiously  increased,  in  order  that  there  may  be  complete  diges- 
tion, which  will  minimize  if  not  entirely  remove  any  depressing 
action  of  the  liberated  toxophore.  Thirty  thousand  killed  bac- 
teria grown  from  material  taken  from  an  apical  abscess  have 
been  known  to  cause  such  a  severe  reaction  that  a  further  re- 
duction in  dosage  has  been  made  and  with  final  beneficial 
results.  After  a  dose  of  vaccine,  if  there  is  fever  or  depres- 
sion lasting  over  a  day,  it  is  a  sure  sign  that  the  interval  be- 
tween doses  should  be  lengthened  or  the  dose  decreased,  or 
both.  Sometimes  a  patient  may  stand  a  given  dose  for  five 
or  six  times  at  weekly  intervals,  and  then  suddenly  show  signs 
of  nausea  or  cerebral  or  ocular  congestion.  These  are  sjnnp- 
toms  that  should  never  be  disregarded.  The  vaccine  should 
be  stopped  for  two  weeks  or  more,  until  the  symptoms  have 
entirely  ceased,  and  then  the  minimum  dose  should  be  given 
again,  and  slowly  raised,  great  care  being  taken  to  stop  short 
at  the  first  signs  of  the  symptoms  previously  noted.  It 
should  also  be  taken  as  a  cardinal  principle  not  to  increase  the 
size  of  the  dose  while  the  patient  is  receiving  a  quantity  that 
apparently  is  sufficient  to  cause  good  progress.  In  this  respect 
patients  vary  in  a  remarkable  degree.  One  patient  will  show  a 
marked  reaction  to  10,000  streptococci,  while  another  can  easily 
accept  100,000,000. 

The  preparation  of  vaccines  for  use  in  vaccine  therapy  con- 
sists of  taking  one  or  more  species  of  the  infecting  germs,  growing 
these  germs  in  suitable  media,  separating  them  according  to 

^  Wilson  and  Dickson,  "Journal  of  Hygiene,"  vol.  xx,  p.  49. 
^  "Protein  Split  Products,"  p.  471. 


VACCINES   IN   THE   TREATMENT  OF   MOUTH   INFECTION         9 1 

species,  combining  them  in  a  sterile  salt  solution  according  to 
their  recognized  dosage  per  cubic  centimeter,  and  destroying 
their  life  but  not  their  substance  by  heat  or  judiciously  used 
antiseptics.  The  vaccine  having  been  thus  prepared  in  the 
laboratory  is  then  injected  into  healthy  tissue,  which  is 
thereby  stimulated  to  form  the  corresponding  amboceptor. 
This  amboceptor,  combining  with  the  complement,  then  dis- 
solves or  causes  the  digestion  of  the  infecting  germs.  When 
the  Kving  germs  of  infection  have  overpowered  a  certain 
mass  of  tissue  cells,  as  in  the  case  of  a  pyorrhea  pocket, 
these  cells  are  unable  to  form  the  specific  amboceptor  neces- 
sary to  sensitize  the  germs  of  infection  so  that  the  blood  can 
dissolve  them.  If,  however,  these  same  germs  are  killed  without 
destroying  their  protein  substance  and  are  injected  into  healthy 
tissue  in  judicious  quantities,  the  healthy  cells  are  stimulated 
and  trained  in  the  habit  of  producing  the  specific  amboceptor. 
This  amboceptor  then  joins  with  the  complement  and  sensitizes 
or  dissolves  the  infecting  germs  wherever  it  happens  to  meet 
them  in  the  body.  And  this  habit  frequently  lasts,  so  that  the 
cells  always  respond  to  the  stimulation  of  the  specific  individual 
infection,  however  small  the  stimulation  may  be.  It  is,  however, 
evident  that  if  the  infecting  germs  are  in  large  masses  or  depots 
surrounded  by  an  inflammatory  or  protective  wall,  the  ferment 
wiU  not  be  effective,  no  matter  how  high  its  percentage  is  raised 
in  the  blood,  since  it  cannot  reach  the  germs  growing  within  such 
a  defensive  mass.  Therefore  the  vaccine  treatment  will  prove  of 
Httle  value  unless  surgical  means  are  used  to  remove  or  break  up 
the  inflammatory  waU.  For  that  reason  every  means  possible 
should  be  used  to  mechanically  remove  these  bacterial  masses; 
and  when  that  is  accomphshed  the  protective  ferments  in  the 
blood  induced  by  the  vaccine  will  amply  be  able  to  destroy  the 
remnants  of  infection  and  prevent  such  infection  from  travehng 
through  the  blood-current  to  other  parts  of  the  body  and  forming 
new  spots  or  depots  of  infection. 

Autogenous  and  Stock  Vaccines. — ^There  are  tv/o  kinds  of 
vaccine — autogenous  and  stock.  The  former  is  grown  from  germs 
obtained  directly  from  the  seat  of  disease;  the  latter  from  germs 


92  MODERN  DENTISTRY 

that  have  the  same  microscopic  and  cultural  characteristics,  but 
are  obtained  from  various  outside  sources.  The  value  of  autog- 
enous vaccine  lies  in  the  fact  that  the  vaccine  is  derived  from 
onl}'^  those  germs  with  which  the  body  is  already  infected.  Two 
germs  may  show  the  same  characteristics  according  to  the  micro- 
scopic analysis  and  growth  on  culture-media,  and  yet  be  essen- 
tially different  in  their  pathologic  reaction.  It  is  clear,  there- 
fore, that  the  autogenous  vaccine,  scientifically  made  from  the 
invading  infection,  must  induce  the  production  of  the  appro- 
priate amboceptor,  while  the  stock  vaccine  may  or  may  not  do 
so.  The  stock  vaccine,  however,  has  the  advantage  of  being  at 
once  available,  while  the  preparation  of  the  autogenous  vaccine 
takes  from  one  to  two  weeks.  Immediate  availability  is  a  great 
advantage  in  acute,  rapidly  spreading  infections  where  prompt 
treatment  is  desirable ;  but  in  chronic  inflammations,  such  as  those 
around  the  gums,  this  haste  is  usually  not  needed.  The  stock 
vaccine  prepared  from  germs  similar  in  appearance  and  growth 
to  the  germs  found  in  the  infected  area  may  produce  the  exact 
amboceptor,  may  merely  produce  a  similar  one  which  is  partly 
effective,  or  it  may  produce  an  antibody  that  has  no  curative 
action  at  all  on  the  disease  to  be  combated.  The  stock  vaccine 
has  the  great  advantage  that  all  the  germs  known  to  be  gener- 
ally associated  with  a  disease  can  be  incorporated  in  that  vaccine, 
while  material  taken  for  an  autogenous  vaccine  may  not  contain 
all  of  the  important  germs,  some  of  which  may  He  too  deep  to 
be  obtained,  or  may  temporarily  be  missing  in  the  spot  of 
infection  from  which  the  parent  germs  of  the  vaccine  are 
obtained. 

While  both  vaccines  have  their  advantages  in  the  treatment  of 
mouth  infection,  it  is  perhaps  the  more  conservative  treatment 
in  ordinary  cases  to  start  with  an  autogenous  vaccine  whenever 
efficient  laboratory  facilities  are  at  hand;  but  where  these  facili- 
ties are  not  available  a  stock  vaccine,  containing  the  principal 
germs  usually  associated  with  the  pockets  of  infection,  will  prove 
valuable. 

There  are  in  the  human  mouth  innumerable  types  of  germs 
that  are  present  and  grow  according  to  the  food  eaten  and  the 


VACCINES    IN    THE    TREATMENT    OF    MOUTH   INFECTION         93 

condition  of  the  saliva.  In  fact,  there  is  hardly  any  germ  that 
may  not  gain  entrance  to  the  mouth.  Therefore,  in  obtaining 
the  parent  germs  for  an  autogenous  vaccine,  if  great  care  is  not 
taken  to  obtain  only  those  germs  found  deep  within  the  pus 
pocket,  or  within  the  actual  walls  of  the  inflamed  region,  an  un- 
limited number  of  extraneous  germs  may  be  taken,  which  would 
give  a  vaccine  not  only  of  practically  no  value  in  restoring 
the  infected  region,  but  would  subject  the  system  to  unnecessary 
strain.  For  instance,  supposing  some  yeast  or  cheese  germs 
were  obtained  from  the  remnants  of  bread  or  cheese  left  around 
the  teeth,  obviously  a  vaccine  obtained  from  such  accidental 
flora  could  not  be  expected  to  cure  pyorrhea.  In  the  same  way 
there  are  doubtless  many  germs  inhabiting  the  mouth  that  are, 
as  one  might  say,  accidental,  and  the  incorporation  of  these  in 
an  autogenous  vaccine  may  explain  many  of  the  failures  of  vaccine 
treatment.  As  before  stated,  only  the  germs  deep  within  the 
infected  pockets  and  within  the  infected  tissues  should  be  used, 
and  the  method  by  which  these  parent  germs  can  be  obtained  to 
the  exclusion  of  all  others  will  now  be  discussed. 

Obtaining  the  Parent  Germs  for  a  Vaccine. — When  the  in- 
fected area  appears  at  the  tip  of  a  root  where  the  pulp  has  died 
and  the  root  canal  has  been  filled,  the  root  canal  should  be 
drilled  out  with  a  fine  sterilized  piano-wire  drill,  until  the  end  of 
the  root  is  nearly  reached.  The  canal  should  then  be  sterilized 
with  a  hot  electric  silver  sterilizer.  When  this  has  been  done  and 
the  tooth  has  been  carefully  guarded  with  a  napkin  to  prevent 
infection  from  the  mouth,  another  sterilized  drill  should  be  passed 
down  to  the  end  of  the  canal  and  plunged  through  the  tip  into 
the  infected  area.  This  drill  should  then  be  carefully  removed 
and  streaked  over  blood-agar  in  such  a  way  that  the  drill  touches 
nothing  in  its  passage  from  the  tooth  to  the  tube  containing  the 
blood-agar.  The  mouth  of  the  tube  should  be  passed  through 
a  flame  both  before  and  after  removing  the  cotton  plug,  and  the 
plug  should  be  held  between  the  second  and  third  fingers  of  the 
hand  holding  the  drill.  The  tube  itself  should  always  be  held 
on  its  side,  so  that  germs  from  the  air  cannot  fall  upon  the  nutri- 
ent material.     The  tube  should  be  carefully  labeled  with  the  name 


94  MODERN  DENTISTRY 

of  the  patient,  the  date  the  material  is  obtained,  and  the  name  of 
the  doctor  obtaining  it.  A  good  way  is  to  write  directly  on  the 
tube  with  a  small  rapidly  revolving  engine  stone.  This  will 
prevent  the  possibility  of  the  label  falling  off  and  consequent 
mistakes  in  the  laboratory.  The  tube  should  then  be  sent  to 
the  laboratory,  and  the  growths  planted  as  soon  as  possible. 

When  the  area  of  infection  appears  near  the  tip  of  a  root  in 
which  the  pulp  is  alive,  the  following  method  should  be  employed: 
The  mucous  membrane  over  the  indurated  spot  should  be  anes- 
thetized and  a  thin  cautery  (see  Fig.  25)  plunged  down  to  the 
bone.  An  opening  should  then  be  made  through  the  outer  plate 
of  the  alveolar  process  by  a  steriKzed  bone-drill.     At  the  end  of 


:^ 


Fig.  34. — Instrument  for  obtaining  material  for  autogenous  vaccine.  The 
platinum  spear  is  set  in  a  ball-and-socket  joint  which  is  loosened  or  tightened  by 
the  ratchet  at  the  end  of  the  handle.  Dotted  lines  indicate  various  positions  the 
spear  can  assume.  After  material  is  obtained  the  instrument  should  be  pointed 
downward  and  the  socket  loosened  until  the  spear  drops  into  a  straight  line  with 
the  instrument,  then  fastened  into  position  by  a  turn  of  the  screw-head,  when  the 
instrument  can  readily  enter  the  test-tube.     (Author's  instrument.) 

two  days  the  outer  opening  in  the  gum  should  be  protected  by 
a  napkin,  anesthetized,  and  cauterized  again.  The  point  of  a 
small  sterilized  platinum-pointed  glass  syringe  or  platinum  spear 
should  then  be  inserted  into  the  bony  opening,  and,  with  the  same 
care  previously  mentioned,  a  drop  of  bloody  fluid  extracted  and 
transferred  to  the  blood-agar  tube.  This  material  will  un- 
questionably contain  the  bacteria  from  the  infected  area  that  have 
gathered  and  grown  during  the  two  intervening  days,  owing  to 
the  lowered  vitality  of  the  wounded  tissue. 

In  taking  a  specimen  from  a  pyorrhea  pocket  the  following 
method  should  be  used:  The  tooth  should  be  protected  from 
mouth  contamination  by  a  sterilized  cotton  roll,  the  neck  of  the 


VACCINES   IN  THE   TREATMENT  OF  MOUTH  INFECTION 


95 


tooth  should  then  be  washed  with  sterile  cotton  dipped  in  sterile 
salt  solution  so  as  to  remove  outside  bacteria  as  much  as  possible, 
and  the  mouth  of  the  pocket  and  adjacent  tooth  neck  should 
then  be  slightly  seared  with  the  cautery.  This  can  be  done 
without  pain  to  the  patient.  Then  a  small  cup-shaped  spear 
of  thin  platinum  (Fig.  34)  should  be  heated  to  a  cherry  red  and 
plunged  to  the  bottom  of  the  pocket.  In  this  way  a  twofold 
purpose  is  at  once  accompKshed — the  extraneous  germs  near 
the  edge  are  destroyed  by  cauterization  and  the  deep-seated 
germs  alone  are  collected  on  the  thin  platinum  point,  which  has 


Ja ^J  2^ 


^^ 


Fig-  35- — Streptococcus. 

cooled  before  reaching  them.  This  renders  it  possible  to  carrj' 
to  the  blood-agar  only  the  germs  presumably  responsible  for  the 
disease  in  question.  It  must  not  be  forgotten  that  pus  is  some- 
times sterile  and  the  true  cause  of  infection  probably  lies  within 
the  walls  of  the  abscess,  and  it  is,  therefore,  from  that  region 
alone  that  the  material  for  the  vaccine  should  be  obtained. 

In  a  study  of  over  300  cases  the  germs  most  frequently 
and  consistently  found  were:  streptococcus,  present  in  95  per 
cent,  of  the  cases;  Micrococcus  catarrhalis  and  Bacillus  in- 
fluenzae in  about  80  per  cent.,  appearing  together;  pneumococcus, 


96  MODERN   DENTISTRY 

staphylococcus,  and  diphtheroids  in  a  percentage  sufficiently 
consistent  to  indicate  their  probably  great  importance,  and 
finally  a  scattering  of  Friedlander's  bacillus.  Micrococcus  tetra- 
genus,  and  a  few  unidentified  germs. 

All  the  germs  found  except  the  spore  formers  are  used  in 
the  preparation  of  the  vaccine.  Staphylococci  should  show 
300,000,000  to  .  the  cubic  centimeter;  streptococci,  diph- 
theroids, pneumococci,  Friedlander's  bacillus.  Micrococcus 
tetragenus,  and  unclassified  bacteria,  50,000,000  each  to  the 
cubic  centimeter.     Where   several   strains  of    streptococci    are 


Fig.  36. — Bacillus  influenzae. 

found,  they  are  usually  combined  so  that  all  the  strains  mixed 
together  will  not  give  over  100,000,000  to  the  cubic  centimeter. 
In  ordinary  cases  of  chronic  pyorrhea  the  initial  dose  originally 
given  by  the  author  was  o.i  of  i  c.c,  and  the  dose  was  steadily 
raised  according  to  the  reaction  at  the  site  of  inoculation,  and 
the  systemic  response.  If  the  patient  showed  exceptional  frail- 
ness, or  the  inflammation  was  unusually  acute,  or  the  blood- 
count  showed  either  a  marked  leukocytosis  or  lymphocytosis, 
the  initial  dose  was  made  much  smaller.  But  it  is  the  author's 
practice  now  in  every  instance  to  start  with  much  smaller  doses. 


VACCINES   IN   THE   TREATMENT   OF   MOUTH   INFECTION         97 

This  is  accomplished  by  having  a  second  bottle  of  the  vaccine 
which  contains  a  dilution  of  one- tenth  or  even  one  one-hun- 
dredth of  the  original  mixture,  and  in  these  cases  it  is  astonishing 
how  often  the  minute  dose  will  result  in  a  satisfactory  improve- 
ment. These  doses  are  generally  given  a  week  apart  in  the 
arm  or  leg.  When  the  hemoglobin  is  low  or  there  is  poiki- 
locytosis  the  dosage  should  be  watched  with  great  care. 

On  account  of  the  consistency  with  which  certain  germs  were 
found  in  gum  infections  it  was  considered  that  these  were  truly 
pathogenic  and,  therefore,  valuable  in  the  preparation  of  a  stock 


Fig.  37. — Micrococcus  catarrhalis. 

vaccine.  These  germs  are  staphylococcus — aureus  and  albus — 
streptococcus  viridans,  bacillus  iniluenzse,  pneumococcus,  mi- 
crococcus catarrhalis,  and  diphtheroids.  These  germs  are  so  fre- 
quently present  that  their  presence  cannot  be  considered  without 
significance;  for  it  must  not  be  forgotten  that  germs  harmless 
to  normal  and  healthy  tissue  may  assume  virulent  pathologic 
characteristics  when  nourished  in  a  mass  of  impoverished  or 
broken-down  cells.  The  germs  used  in  this  stock  vaccine  were 
obtained  by  mixing  all  the  germs  of  similar  types  as  they  occurred 
in  about  loo  of  my  cases.  For  instance,  all  the  different 
7 


98  MODERN  DENTISTRY 

strains  of  staphylococci  were  mLxed  together  and  the  resultant 
staphylococcus  was  the  one  used  in  the  vaccine.  The  same  pro- 
cedure was  followed  with  the  other  types  mentioned.  This 
was  done  so  that  the  various  germs,  when  injected,  would  make 
ferments  that  would  have  a  broad  specific  action  on  the  various 
strains  of  bacteria  to  be  combated.  Such  a  vaccine  is  of  special 
value  to  those  practitioners  who  do  not  have  a  laboratory  at 


Fig.  38. — Pneumococcus  capsulatus.  This  germ  when  it  infects  the  lungs  and 
causes  pneumonia  results  in  a  frightful  mortality  owing  to  the  mucilaginous  capsule 
that  surrounds  it.  This  capsule  is  particularly  well  shown  on  the  three  organisms 
in  lower  portion  of  the  plate.  In  one  case  material  taken  from  a  pus-pocket 
around  a  tooth  contained  80  per  cent,  of  this  micro-organism.  After  vaccine 
treatment  the  gums  healed  promptly,  and  repeated  examinations  during  a  period 
of  three  years  failed  to  find  this  germ  anywhere  in  the  tissues  around  the  teeth. 

hand  for  the  preparation  of  autogenous  vaccines.  The  further 
advantage  of  this  stock  vaccine  lies  in  the  fact  that  it  can  be 
sensitized,  if  desired,  with  the  sensitized  serum  of  a  goat,  which 
will  make  it  possible  to  give  it  in  much  larger  doses  than  would 
be  feasible  with  the  ordinary  autogenous  vaccines. 

Sensitized  Vaccine. — If  a  sensitized  vaccine  is  required,  the 
vaccine  should  be  first  made  in  the  ordinary  way,  and  given  in 


VACCINES    IN   THE    TREATMENT   OF    MOUTH    INFECTION         99 

large  doses  to  a  goat  until  the  blood  of  the  goat  is  surcharged 
with  the  corresponding  amboceptors.  Then  the  goat  is  bled 
and  its  serum  containing  the  amboceptors  is  allowed  to  remain  in 
contact  with  the  bacteria  for  twenty-four  hours.  The  material 
is  then  centrifuged  and  the  bacteria  are  washed  with  a  sterile 
salt  solution  until  all  the  free  serum  has  been  removed.  The 
germs  are  then  counted  and  mixed  in  the  proper  proportions  for 
the  vaccine.  In  the  use  of  the  sensitized  stock  vaccine  the  same 
digestion  takes  place  in  the  body  as  with  the  ordmary  vaccines, 
except  that  the  digestion  is  more  rapid  and  complete,  since 
the  amboceptor  obtained  from  the  goat  is  already  joined  to  the 
germs.  Thus  the  protein  poison  is  supposed  to  be  completely 
destroyed,  leaving  the  harmless  protein  products  to  increase 
the  percentage  of  the  therapeutic  amboceptor  in  the  blood. 

As  before  stated,  in  giving  vaccines,  it  must  not  be  "forgotten 
that  a  dose  that  is  borne  with  ease  for  a  number  of  times  in  suc- 
cession may  suddenly  cause  a  severe  reaction.  When  this  is  the 
case  the  same  procedure  should  be  followed  as  though  the  re- 
action came  from  an  increased  dose.  Why  this  occurs  is  not 
known,  but  it  is  possible  and  probable  that  when  the  amboceptor 
in  the  blood  rises  to  an  effective  height  it  suddenly  successfully 
attacks  masses  of  infection  heretofore  resistant,  and  thus  the 
body  has  thrown  upon  it  not  only  the  spHt  products  of  germs 
contained  in  the  vaccine  but  also  all  the  protein  substance  from 
the  germs  destroyed  in  the  body.  An  interesting  symptom  is 
the  occasional  persistance  of  the  lump  or  induration  which  forms 
at  the  point  of  injection.  It  appears  that  this  can  be  due  only  to 
a  lack  of  digestion  and  absorption  of  the  bacterial  bodies  injected. 
So  long  as  the  induration  markedly  persists  we  have  an  indication 
that  the  potentialities  of  the  vaccine  injection  have  not  been 
exhausted.  Therefore,  under  these  conditions,  further  in- 
jections may  be  temporarily  withheld  or  smaller  doses  given, 
while  absorption  in  the  seat  of  induration  may  be  stimulated 
by  massage. 

If  there  is  a  tendency  to  the  rapid  formation  of  creamy  tartar 
deposits  on  the  teeth  prior  to  the  vaccine  treatment,  it  wiU 
be  noted  that  as  the  antibodies  are  formed  and  the  gums  show 


lOO  MODERN  DENTISTRY 

signs  of  healing,  the  tartar  will  be  deposited  much  less  rapidly, 
and  the  tartar  deposited  is  of  a  much  more  solid  and  removable 
nature,  and  does  not  tend  to  burrow  under  the  gum  margins. 
This  change  in  the  deposition  of  tartar  I  have  come  to  consider 
as  a  distinct  symptom  of  the  successful  progress  of  the  vaccine 
inoculation. 

AUen^  speaks  of  the  value  of  citric  acid  in  30-grain  doses, 
three  times  a  day,  for  the  purpose  of  softening  the  lymph  wall 
around  the  foci  of  infection  by  reducing  the  coagulating  power 
of  the  blood.  I  have  found  the  treatment  of  service,  but  give 
it  in  the  form  of  i  ounce  of  lemon  juice  three  times  a  day,  which 
is  the  equivalent  of  about  34  grains  of  citric  acid  for  each  dose. 

When  a  pus  pocket  shows  signs  of  sudden  inflammation  during 
treatment,  it  is  always  wise  to  open  it  surgically,  drilHng  along 
the  root  to  be  sure  that  there  is  no  back  pressure  of  pus  and  that 
the  antibodies  have  full  opportunity  to  enter  the  seat  of  infection. 
For,  above  all  things,  it  should  be  remembered  that  vaccine 
treatment  can  be  successful  only  when  accompanied  by  judicious 
local  treatment  of  a  surgical  and  therapeutic  character. 

When  there  is  active  tuberculosis,  vaccine,  in  my  experience, 
should  be  avoided,  or,  if  given,  it  should  be  given  with  extreme 
caution.  When  there  is  a  history  of  active  tuberculosis  that  has 
healed,  any  cough  or  acute  inflammation  in  the  joints  develop- 
ing during  the  vaccine  treatment  should  be  looked  upon  as  a 
danger  signal.  When  the  glands  suddenly  become  enlarged  and 
the  clinical  thermometer  shows  a  rise  in  the  evening  to  100° 
F.,  or  a  rash  appears  suddenly  over  the  nose  and  upper  cheek 
bones,  the  vaccine  should  be  stopped  altogether  for  a  considerable 
period,  and  if  it  is  recommenced,  a  dose  of  not  over  10,000 
or  20,000  germs  should  be  given  at  the  start,  and  the  daily 
temperature  carefully  noted  as  a  guide.  These  compHcations 
are  rare,  fortunately,  but  nevertheless  should  always  be  recog- 
nized at  their  first  appearance. 

Vaccine  dosage  is  a  problem  that  is  being  solved  by  accredited 
clinicians  in  a  manner  that  theoretically  might  seem  altogether 
to  discredit  vaccine   therapy  as   a   science.     Initial  doses   of 

^  "Vaccine  Therapy  and  Opsonic  Treatment,"  p.  126  (Blakiston). 


VACCINES    IN    THE    TREATMENT   OF   MOUTH   INFECTION       lOI 

500,000,000  to  1,000,000,000  are  given  on  the  one  hand,  while 
other  practitioners  find  that  doses  of  one  one-thousandth  or  even 
one-ten-thousandth  of  these  quantities  give  satisfactory  thera- 
peutic results. 

One  cannot  help  feeHng  that  the  state  of  knowledge  concern- 
ing the  routine  administration  of  vaccines  is  about  the  same  as 
that  held  formerly  in  the  routine  administration  of  calomel  or 
quinin,  when  these  were  first  discovered  and  administered  as 
drugs  — 10-  to  15-grain  doses  of  calomel  were  given,  fre- 
quently with  good  therapeutic  results,  and  then  again  saliva- 
tion sometimes  occurred  under  such  dosage  with  permanent 
injury.  In  the  same  way  quinin  was  frequently  administered 
in  50-  or  60-grain  doses.  When  the  patient  was  not  sensitive 
to  quinin  unquaHfied  good  results  were  obtained,  but  when 
there  was  an  idiosyncrasy,  disastrous  if  not  fatal  effects  were 
encountered. 

Some  seven  years  ago  when  the  author  began  to  give  vaccines 
he  also  used  large  doses.  He  gave  himself  experimentally  forty- 
two  weekly  doses  of  vaccine,  thirty-two  of  which  each  con- 
tained 1,100,000,000  mixed  germs.  The  results  were  excellent. 
But  during  the  first  four  or  five  years  of  his  experience  with  this 
treatment,  he  encountered  very  occasionally,  reactions  so  serious 
that  at  times  he  wondered  whether  the  anxiety  and  worry  made 
the  treatment  worth  while.  However,  satisfactory  cures  were 
obtained  in  90  per  cent,  of  the  cases  without  any  bad  symp- 
toms, so  that  there  was  more  than  suflS.cient  encouragement  to 
persevere.  Nevertheless,  the  result  of  experience  steadily  im- 
pelled the  use  of  smaller  doses,  so  that  instead  of  starting 
with  a  minimum  dose  of  12  to  25  or  even  50  milHon  germs, 
if  the  vaccine  consisted  of  four  or  five  different  species; 
the  chnician  may  now  start  with  a  dose  of  30,000,  and  in 
some  very  exceptional  cases  this  dose  has  to  be  reduced  in- 
stead of  increased.  In  a  certain  percentage  of  cases  it  will 
prove  harmful  to  give  an  initial  dose  of  5  to  10  million 
germs  until  the  tolerance  of  the  patient  is  carefully  ascer- 
tained. An  intense  reaction,  as  shown  by  depression,  fever, 
acute  or  local  inflammation,  or  marked  variations  in  the  blood- 


I02  MODERN  DENTISTRY 

pressure,  is  undesirable.  By  just  avoiding  these  symptoms, 
better  therapeutic  results  will  be  obtained. 

Incredulity  will  be  aroused  by  this  statement,  but  a  little 
consideration  will  show  that  it  is  not  so  preposterous  as  it  may 
at  first  appear.  Webb  has  found  that  one  or  two  living  tubercle 
bacilK  when  injected  hypodermically  are  capable  of  giving  ex- 
cellent clinical  results,  and  Myer  Solis-Cohen  (Archives  of 
Pediatrics,  January,  1918)  has  shown  that  one  ten-millionth 
of  a  milligram  of  tuberculin  residue  may  be  an  effective  dose. 
If  this  is  so,  why  then  should  the  tubercle  bacillus  be  absolutely 
in  a  class  apart  from  all  of  the  other  organisms  that  infect  the 
body?  During  the  last  two  years  the  author  has  been  growing 
cultures  anaerobically  from  material  taken  from  the  tips  of 
extracted  teeth.  Formerly  aerobic  cultures  alone  were  used, 
but  by  anaerobic  cultivation  he  and  his  laboratory  assistant 
appear  to  have  discovered  a  new  Gram-negative  cocco-bacillus 
that  is  associated  with  the  absorption  of  root  tips,  which  germ 
seems  to  have  extreme  virulence  and  toxicity.  This  new  germ 
may  partly  but  not  entirely  account  for  the  reactions  that  oc- 
casion the  reduction  in  dosage. 

It  is  claimed  by  many  observers  that  certain  people  cannot 
advantageously  take  vaccine.  This  statement,  when  applied 
to  autogenous  vaccines,  seems  illogical,  for,  as  a  matter  of  fact, 
the  patient  by  the  mere  presence  of  the  disease  has  already  taken 
the  germs  in  a  living  state.  Any  patient  suffering  from  a  local- 
ized infection  can  safely  and  usually  beneficially  take  an  au- 
togenous vaccine  prepared  from  the  localized  infection  if  judi- 
cious dosage  is  employed.  And  so  again,  we  come  back  to  the 
question  of  dosage.  The  determination  of  the  size  of  the  dose 
depends  primarily  on  the  interpretation  of  what  constitutes 
a  true  reaction,  and  this  interpretation  is  dependent  upon  a 
nice  discrimination. 

Seven  or  eight  years  ago  the  general  procedure  was  to  start 
treating  a  so-called  normal  patient  with  12,000,000  to  25,000,000 
germs.  If  the  patient  showed  depression  or  fever  that  did  not 
last  twelve  hours  the  dose  was  doubled,  and  after  a  while  it  was 
again  doubled,  and  doubled  again,  until  incredibly  large  doses  were 


VACCINES   IN  THE   TREATMENT   OF   MOUTH   INFECTION      I03 

given,  the  patient  each  time  getting  a  terrific  therapeutic  bump. 
If  the  patient  did  not  get  a  bump  the  dose  was  increased,  and 
if  he  did  get  a  bump  the  dose  was  also  increased,  because  it  was 
noted  by  many  authors  and  clinicians  that  those  patients  who 
had  the  worst  reactions  made  the  best  recoveries.  And  so  the 
rather  loose  philosophy  of  vaccine  dosage  seemed  to  be,  "Give 
the  patient  small  doses  at  first  and  increase  them  so  as  not  to 
have  too  great  a  reaction,  but  if  the  patient  does  have  too  great 
reaction  he  will  have  a  better  recovery."  Either  way  it's  all 
right,  and — strange  to  say — this  vague  unphilosophic  theory  of 
dosage  seems  ordinarily  to  have  worked  out  very  well. 

The  large  doses  administered  gave  good  results  and  still 
do  give  good  results  in  a  great  majority  of  cases,  but  in  a  small 
though  important  percentage  of  cases  they  still  do  harm,  and  as 
the  unfortunate  results  always  make  a  greater  impression  than 
the  good  results  it  was  not  surprising  that  many  physicians  gave 
up  the  use  of  vaccines  altogether.  Many  thousands  of  ])hy- 
sicians  were  getting  such  good  results,  however,  that  the  des- 
pairing cries  from  some  esteemed  leaders  were  not  sufficiently 
conclusive  to  make  them  discard  vaccines.  Many  of  us  felt 
too  sure  of  the  value  of  the  treatment  to  be  stampeded  by 
crudities  that  must  of  necessity  be  remedied  in  the  near 
future. 

In  the  author's  opinion  there  must  be  more  careful  inves- 
tigation into  the  effect  of  small  doses  of  vaccine.  Doses  of 
150,000,000  to  300,000,000  germs  are  still  given  by  the  au- 
thor, but  invariably  a  small  dose  is  given  first.  The  aver- 
age patient  with  his  various  latent  infections,  is  very  much 
in  the  position  of  a  many  chambered  magazine  containing 
powder,  that  must  be  touched  off  without  blowing  out  the 
sides  of  the  building.  If  each  room  of  the  magazine  has  small 
quantities  of  powder  in  it  and  the  powder  is  sHghtly  damp 
or  slow-burning,  the  task  is  comparatively  simple  and  one  room 
at  a  time  can  be  safely  fired  by  a  judicious  explosive  charge. 
On  the  other  hand,  if  there  are  an  infinite  number  of  compart- 
ments each  full  of  explosive,  and  instead  of  slow-burning  powder 
we  have  dynamite,  the  difficulty  is  greatly  increased  and  much 


I04  MODERN    DENTISTRY 

greater  caution  in  the  size  of  the  explosive  charge  must  be 
used. 

Let  us  now  recite  briefly  a  few  cases  that  have  reacted  in 
an  astonishing  way  to  small  vaccine  doses.  There  are  many 
other  cases  that  could  be  quoted  that  unmistakably  responded 
clinically  to  small  doses,  but  a  mere  piling  up  of  cases  would  be 
tedious  and  unconvincing. 

The  first  case  was  a  man  aged  forty,  who  had  gouty  deposits 
in  the  ears,  crepitus  and  pains  in  the  knee-joints,  associated  with 
sharp  pains  along  the  tendons  of  the  thighs  and  legs  whenever 
he  walked — a  typical  case  of  systemic  infection  from  diseased 
teeth  and  gums.  The  infected  teeth  were  extracted  and  an 
autogenous  vaccine  was  made.  The  first  dose  of  150,000  germs 
made  him  uncomfortable,  the  second  dose,  a  week  later,  of 
210,000  germs  sent  him  to  bed  with  inflammatory  fever,  painful 
joints,  and  swollen  ears.  After  two  weeks  when  the  symptoms 
subsided  a  dose  of  30,000  germs  was  given  that  made  his  ears 
swell  a  little,  but  the  dose  was  well  borne.  At  four  weekly 
intervals  he  was  given  30,000  germs,  with  marked  improvement. 
Then  he  was  given  60,000  germs  and  promptly  went  to  bed 
again,  this  time  for  only  two  days.  Then  30,000  germs  were 
given  at  weekly  intervals  for  six  times,  and  he  made  a  most 
satisfactory  recovery. 

There  are  other  cases  where  the  patient  showed  marked 
improvement  and  also  marked  systemic  reaction  to  weekly 
doses  of  6000  to  15,000  germs,  but  one  is  of  especial  interest — 
that  of  a  married  woman,  aged  thirty-six,  of  the  systemic  in- 
flammatory t3^e,  teeth  sensitive  to  heat  and  cold,  resisting  all 
treatment.  When  she  came  for  treatment  she  had  just  weaned 
her  baby.  The  first  dose  of  30,000  germs  caused  her  breasts 
to  become  painful  and  to  swell.  There  was  also  a  vaginal  dis- 
charge and  she  was  depressed  and  ached  all  over.  A  week  later 
she  was  given  15,000  germs,  with  similar  reactions  but  less 
marked,  and  these  symptoms  recurred  seven  times  at  weekly 
intervals,  although  the  dose  was  reduced  to  9000  germs.  The 
breast  and  vaginal  reactions  are  particularly  interesting,  as  they 
could  not  have  been  the  result  of  neurasthenia   or  hysteria. 


VACCINES   IN  THE   TREATMENT   OF   MOUTH   INFECTION      105 

Meantime  she  showed  marked  improvement  and  the  teeth  were 
successfully  treated  and  filled  in  a  manner  theretofore  quite 
impossible. 

Another  case  is  that  of  a  woman  aged  sixty-two,  who  could 
not  bear  30,000  germs  without  a  severe  reaction,  but  could  stand 
15,000  germs.  Finally,  60,000  germs  were  tried  as  a  test,  and 
she  had  great  depression  and  lymphatic  enlargement,  especially 
in  the  groins.  For  two  days  she  was  so  weak  that  she  required 
cardiac  stimulants. 

In  closing  the  discussion  of  dosage  it  might  be  well  to  state 
the  present  method  of  the  author  for  ascertaining  the  proper 
vaccine  dose.  Thirty  thousand  germs  are  usually  given  at 
the  start  and  raised  by  weekly  doses  so  long  as  the  patient 
bears  the  dose  well,  even  if  the  dose  goes  up  to  1,000,000,000. 
However,  when  the  patient  is  showing  satisfactory  improvement 
under  a  dose,  that  dose  is  maintained.  If  30,000  germs  are  not 
accepted  easily,  the  dose  should  be  reduced  to  a  number  that 
is  easily  accepted.  It  is  also  especially  important  that  the 
patient  should  be  carefully  watched  for  reactions. 

When  grip  and  colds  are  prevalent  the  patient  who  is  given 
a  dose  that  cannot  readily  be  borne  is  apt  to  get  sore  throat  or 
grip.  Such  an  attack  must  be  regarded  not  as  an  unimportant, 
accidental  symptom.  It  should  always  be  regarded  as  a  possible 
reaction  calling  for  dose  reduction,  and  if  the  cold  or  grip  should 
recur  regularly  with  the  vaccine  administration,  its  recurrence 
should  be  considered  conclusive  evidence  that  the  sore  throat, 
cold,  or  grip  is  a  real  reaction,  calling  for  a  corresponding  modi- 
fication in  dosage. 

It  has  been  the  author's  experience  that  reactions  occur  in 
widely  different  forms  and  require  most  careful  analysis  on  the 
part  of  the  physician  if  the  best  results  for  the  patient  are  to  be 
obtained.  It  has  also  been  his  experience  that  large  doses  given 
at  the  start  seem  to  mask  a  fine  gradation  of  symptoms  by 
which  a  just  analysis  of  the  patient's  needs  may  be  ascertained. 
Large  doses  may  be  accepted  by  the  body  when  roused  to  com- 
bat a  pathologic  assault,  and  being  aroused,  it  protects  itself, 
but  at  the  same  time  finds  its  energies  exhausted,  while  the 


Io6  MODERN  DENTISTRY 

exactly  ascertained  dose  that  will  just  stop  short  of  a  reaction, 
will  philosophically  give  the  best  therapeutic  effect. 

The  author's  vaccines  are  standardized  by  Wright's  method 
Controlled  by  turbidity  tests. 

Vaccines  and  Anemia. — A  patient  came  to  me  with  a  hemo- 
globin of  30  per  cent.,  red  cells  3,616,000,  white  cells  4500, 
with  microcytes,  macrocytes,  and  poikilocytes.  The  patient 
was  so  weak  that  she  could  hardly  walk.  I  extracted  three 
roots  and  put  her  mouth  under  proper  cleansing,  and  in  five 
days  her  hemoglobin  rose  to  37  per  cent.,  the  macrocytes, 
microcytes,  and  poikilocytes  disappeared,  and  the  red  cells 
began  to  accept  the  stain  in  a  more  normal  manner.  She 
was  advised  to  take  3  raw  eggs  three  times  a  day  before  meals, 
and  the  vaccine,  composed  of  i  diphtheroid,  i  pigmented 
streptococcus,  and  i  non-hemolytic  streptococcus,  was  given 
once  a  week.  For  a  while  improvement  hung  fire.  After  each 
dose  of  vaccine  the  hemoglobin  would  drop  during  two  days 
through  a  range  of  3  or  4  points,  and  then  it  would  slowly 
climb  up  a  Kttle  higher  than  at  the  start,  so  that  gradually  the 
hemoglobin  reached  50  or  more;  the  red  cells  rose  to  over  4,000,000 
and  the  leukocytes  to  9000  or  10,000.  The  patient's  eyes  lost 
their  yellow  cast  and,  from  being  hardly  able  to  walk,  she  steadily 
increased  in  strength  so  that  she  felt  better  than  she  had  in  years. 
In  this  case,  without  the  blood-count  as  a  guide,  the  vaccine 
might  have  resulted  in  disaster. 

Vaccines  and  Osteo-arthritis. — Two  cases  of  pronounced 
osteo-arthritis  evidently  caused  by  mouth  infection  will  now 
be  given.  The  first  was  that  of  a  man  who  had  been  suffering 
for  three  years  with  rapidly  progressing  arthritis  deformans, 
associated  with  hardening  of  the  arteries.  He  was  just  able 
to  walk  with  the  aid  of  two  canes.  He  came  to  me  as  a  last 
resort  for  a  possible  slight  relief.  I  found  three  necrotic  teeth 
which  I  extracted.  There  were  numerous  Hve  infected  pulps 
that  were  removed  and  the  canals  antiseptically  filled.  The 
pockets  of  infection  were  invariably  associated  with  loose,  pain- 
ful teeth.  The  pockets  of  infection  were  treated  surgically, 
a  scientific  mouth  hygiene  was  instituted  (see  Chapter  II),  the 


VACCINES   IN   THE   TREATMENT   OF   MOUTH   INFECTION       107 

pockets  were  syringed  with  bifluorid  of  ammonium,  and  the 

patient  cautiously  given  autogenous  vaccine  once  a  week.  At  the 

end  of  the  fourth  week  he  took  off  his  iron  boot  and  was  able  to 

walk  with  but  one  cane.     He  soon  was  able  to  bend  his  knees 

and  cross  his  legs,  which  before  had  been  impossible.     Before 

long  he  walked  from  the  station  to  my  office,  a  distance  of  half 

a  mile,  and  finally,  in  about  six  weeks,  was  able  to  walk  a  short 

distance  without  the  cane.     In  the  meantime  the  pockets  of 

infection  disappeared,   and  the  teeth  tightened   to   the  point 

where  mastication  was  comfortable  and  effective.     During  the 

administration  of  the  vaccine  he  had  no  reaction  whatever, 

until  finally  after  the  twelfth  administration  the  erythrocytes, 

hemoglobin,  and    leukocytes    suddenly    began    to    drop.     The 

vaccine  was  at  once  stopped  and  he  was  dismissed,  being  put  on 

a  low  protein  diet  and  being  warned  to  keep  up  the  prescribed 

mouth  hygiene.     He  continued  to  improve,  but  in  the  course  of 

a  year  carelessness  in  mouth  hygiene  caused  a  reinfection,  and 

at  the  same  time  brain  symptoms  due  to  hardening  of  the  arteries 

set  in,  so  that  he  was  finally  confined  to  his  chair  through  mental 

inertia.     The  treatment  was  renewed,  and  in  the  course  of  a 

year  he  made  a  satisfactory  recovery  as  far  as  his  joints  and 

inflammatory  symptoms  were  concerned. 

The  other  case  was  one  to  which  I  was  called  in  consultation. 
This  patient,  a  man  aged  sixty-seven,  was  unable  to  move  him- 
self about  without  excessive  pain  in  practically  all  of  his  muscles 
and  joints.  There  were  three  necrotic  teeth  and  pockets  of 
infection  about  the  other  teeth.  The  necrotic  teeth  were  ex- 
tracted, and  an  autogenous  vaccine  made  from  the  infected 
pockets.  He  was  treated  as  has  been  described  in  this  chapter. 
He  came  from  the  hospital  to  my  office  just  four  times,  a  week 
apart.  The  first  two  times  he  came  in  the  ambulance,  the 
third  and  fourth  times  in  the  trolley  cars,  and  walked  with  Httle 
difficulty,  and  then  he  insisted  that  he  was  cured  and  that  he 
was  going  to  his  home  in  West  Virginia.  1  told  him  that  he  was 
foolish,  that  he  was  not  cured,  but  still  he  insisted  and  went, 
and,  much  to  my  surprise,  he  appears  to  have  been  right,  for 
he  kept  on  improving  and  now  gets  in  and  out  of  the  bath-tub 


Io8  MODERN  DENTISTRY 

and  is  in  every  way  normal,  so  his  son,  who  is  a  doctor,  tells  me. 
He  took  the  vaccine  with  him  and  received  weekly  doses  for  a 
period  of  four  months.  His  leukocytes  when  he  entered  the 
hospital  were  15,600,  and  in  two  months  they  had  dropped  to 
9400,  where  they  remained. 

The  discovery  by  Barrett  and  Smith  of  the  ameba  in  the 
pyorrhea  pocket  was  considered  most  important  as  presenting 
the  possible  cause  of  mouth  infection,  and  consequently  ipecac 
and  its  alkaloid,  emetin,  have  been  given  in  numerous  instances  as 
a  possible  specific  in  this  disease.  I  have  used  emetin,  f  grain, 
administered  h3Apodermically  in  the  arm  or  back  for  ten  suc- 
cessive days  during  the  treatment  of  mouth  infection,  but  have 
no  reason  to  beHeve  that  it  is  of  great  value.  I  have  also  used 
it  in  local  appHcations,  but  have  felt  that  in  this  respect  it  is  less 
valuable  than  the  bifluorid  ammonium  comp.  This  would 
indicate  that  the  ameba  is  not  the  specific  cause  of  mouth 
infection.  In  my  opinion,  no  single  drug  or  vaccine  can  ehminate 
mouth  infection  when  it  is  once  intrenched.  It  can  only  be  cured 
by  the  judicious  dentist,  who  must  determine  just  what  surgical 
and  therapeutic  procedures  will  be  effective.  Any  specific  cura- 
tive claim  for  surgery,  vaccine,  or  drugs  alone  will  certainly 
retard,  not  advance,  the  cure  of  mouth  infection. 

In  closing  this  chapter  I  would  emphasize  the  necessity  for  a 
complete  preKminary  study  of  the  patient  by  a  competent 
physician  who  will  diagnose,  as  well  as  may  be,  the  condition  of 
all  the  organs  of  the  body,  so  that  when  the  vaccine  is  given, 
this  diagnosis  may  be  borne  in  mind  and  the  dosage  modified 
accordingly. 


CHAPTER  VI 

TREATMENT   OF  ROOT  CANALS 

EXCISION   OF   INFECTED    OR   NECROTIC   ROOTS 

Alveolar  Abscess. — One  of  the  most  important  causes  of 
mouth  infection  is  the  alveolar  abscess,  due  to  deterioration 
of  the  dental  pulp  which  forms  the  tooth  bone  or  dentin.  The 
term  "dental  pulp"  will  be  used  to  designate  the  mass  of  sensitive 
tissue  within  the  tooth,  that  among  the  laity  is  generally  desig- 
nated as  the  tooth  "nerve." 

After  a  tooth  has  been  erupted  for  a  period  of  from  eight  to 
ten  years  the  essential  constructive  work  of  the  pulp  may  be 
said  to  have  been  finished.  From  then  on  it  slowly  shrinks 
within  the  bony  walls  which  it  still  continues  to  gradually  form, 
and  on  the  sKghtest  provocation  accepts  infection  and  calcic 
infiltration,  so  that  from  being  a  benefit  it  is  a  distinct  burden 
and  menace  to  the  usefulness  and  health  of  the  tooth.  The 
chief  source  of  nourishment  of  a  developed  tooth  is  found  in  the 
peridental  membrane  that  envelops  the  root  or  roots,  and  this 
membrane  is  amply  able  to  maintain  the  tooth  in  comfort  and 
stability  if  there  is  no  comphcation  occasioned  by  infection  and 
nerve  irritation.  If  the  pulp  is  a  healthy,  nourishing  one,  it  is 
of  unquestioned  benefit  to  the  tooth,  but  when  it  becomes  in- 
fected and  irritated  so  as  to  be  a  depressing  burden,  the  sooner 
it  is  removed  the  better,  leaving  the  healthy  peridental  membrane 
to  fulfil  the  functions  of  maintenance  and  nutrition.  But  if 
through  the  infection  of  the  pulp  the  peridental  membrane  also 
becomes  irritated  and  infected,  the  tooth  will  become  loose  and 
in  danger  of  being  lost. 

A  comparatively  smaU  cavity  in  a  tooth  will  allow  infecting 
organisms  to  reach  the  pulp  that  may  or  may  not  repel  the  in- 
vasion, but  when  the  soft  decay  itself  reaches  the  pulp,  so  that 

109 


no  MODERN  DENTISTRY 

its  removal  causes  an  obvious  exposure,  the  pulp  must  be  re- 
moved and  the  root  canals  filled.    Any  other  procedure  is  in- 
excusable.   Many  an  alveolar  abscess  is  derived  from  an  infected 
pulp  and  will  resist  all  treatment  until  the  pulp  is  removed,  and 
then  the  abscess  will  heal  of  itself.    Many  a  loose  tooth  will 
refuse  to  yield  to  the  treatment  designed  to  tighten  it  until  the 
living  pulp  is  removed,  and  then  it  will  rapidly  become  firm. 
Many  times  a  double-rooted  tooth  apparently  sound  and  un- 
decayed  has  developed  soreness,  looseness,  and  supersensibility 
to  heat  and  cold.    A  careful  exploration  will  show  that  one  of 
the  roots  has  become  infected  at  the  tip  by  a  peridental  abscess, 
which  has  destroyed  the  blood  circulation  in  the  canal  of  the 
root,  thereby  rendering  the  pulp  half-dead  and  half-alive — a 
menace  not  only  to  the  welfare  of  the  tooth  and  jaw,  but  to  the 
health  of  the  entire  body.     Therefore,  when  the  pulp  of  a  tooth 
is  exposed  through  decay,  or  when  there  is  excessive  response 
to  heat  or  cold,  or  when  peridental  inflammation  is  combined 
with  looseness  and  there  is  no  response  to  thermal  change, 
the  pulp  should  be  removed  and  the  canals  sterilized  and  properly 
filled.    Where,  however,  all  the  teeth  become  sensitive  at  once 
or  are  insensitive  to  thermal  change,  we  must  look  for  a  systemic 
cause   or   an   idiosyncrasy.     Spinal   irritation   associated   with 
osteoarthritis,  lead-  or  mercury-poisoning,  or  even  an  onset  of 
grip  may  cause  a  general  type  of  irritation  which  will  frequently 
depart  with  the  subsidence  of  the  systemic  lesion.     It  must 
be  remembered  that  some  teeth  are  naturally  insensitive,  an 
idiosyncrasy  occasionally  found,  and  it  would  obviously  be  ill- 
advised  to  destroy  the  pulps  in  teeth  that  had  the  general  charac- 
teristic of  insensibility  as  their  sole  pathologic  symptom.     How- 
ever, there  will  ordinarily  be  no  difiiculty  in  differentiating  be- 
tween the  local  and  general  disturbance,  since  with  the  local  cause 
there  will  be  great  variations  in  the  individual  teeth,  while  with 
the  idios5^crasy  or  general  cause  all  the  teeth  will  be  affected 
in  practically  the  same  manner. 

Local  Anesthesia. — In  inducing  local  anesthesia  the  author 
has  found  the  Farbwerke-Hoechst  tablets  of  novocain-suprarenin 
to  give  the  best  results,  the  tablet  marked  E,  containing  0.02  gm. 


TREATMENT  OF  ROOT  CANALS 


III 


or  ^  grain  of  novocain  with  0.00005  gram  of  suprarenin,  being 
the  one  usually  used.  The  best  results  are  obtained  by  dis- 
solving the  tablet  in  2  or  even  4  c.c.  of  Ringer's  solution,  which 
makes  a  i  or  0.5  per  cent,  solution.  A  sterile  normal  salt  solu- 
tion containing  0.7  per  cent,  chlorid  of  sodium  has  been  used  for 
this  purpose  in  order  that  the  percentage  of  salt  injected  should 
be  the  same  as  the  salt  in  the  blood-serum,  and  this  has  given 
good  results,  but  the  Ringer  solution  is  less  irritating  to  the  tis- 


Fig.  39. — A,  glass  flask  in  which  Ringer's  solution  can  be  sterilized;  5,  suitable 
casserole  in  which  solution  of  novocain  and  suprarenin  can  be  dissolved  and  finally 
sterilized  by  boiling. 


sues  and  is  productive  of  more  rapid  infiltration  and  anesthesia. 
This  is  no  doubt  largely  due  to  the  calcium  chlorid  which  is 
present.  The  Ringer  solution  is  made  by  dissolving  i  Ringer 
tablet  in  10  c.c.  of  distilled  water.  It  contains  sodium  chlorid 
0.5  per  cent.,  calcium  chlorid  0.04  per  cent.,  and  potassium  chlorid 
0.02  per  cent.  Distilled  water  must  be  used  for  the  solution,  as 
the  suprarenin  is  seriously  affected  by  any  alkaline  traces.  The 
flask  recommended  by  Reithmiiller,  as  shown  in  Fig.  39,  A, 


112  MODERN  DENTISTRY 

for  holding  the  solution,  is  excellent  and  practical.  The  solution 
should  be  made  up  as  described  and  sterilized  for  ten  minutes, 
preferably  in  a  small  electric  sterilizer.  When  it  is  cooled  it 
should  be  put  aside  for  use  as  needed.  When  the  novocain- 
suprarenin  solution  is  to  be  made,  2  or  4  c.c.  of  the  solution  should 
be  poured  out  of  the  flask  into  the  porcelain  casserole  recom- 
mended by  Fischer,  shown  in  Fig.  39,  B,  and  raised  to  the  boiling- 
point.  While  hot,  one  of  the  E  tablets  should  be  added  to  make 
either  a  i  or  |  per  cent,  solution,  and  the  mixture  again  raised  to 
the  boiling-point.  It  should  then  be  drawn  into  a  sterile  syringe 
and  injected  at  blood  temperature  into  the  tissues,  the  spot  of 
injection  being  first  touched  with  alcohol  or  tincture  of  iodin. 
The  solution  should  remain  clear.  If  it  turns  reddish  or  is  floc- 
culent  it  should  be  thrown  away  as  unfit  for  use.  Such  changes 
usually  occur  because  distilled  water  was  not  used  for  making 
up  the  mixture.  The  anesthetizing  solution  should  be  freshly 
prepared  for  each  operation,  as  it  quickly  deteriorates.  The 
great  advantage  in  using  the  tablets  hes  in  the  fact  that  they  will 
not  deteriorate  so  long  as  they  are  kept  dry  and  sealed,  and  also 
in  the  fact  that  as  they  contain  a  fixed  amount  of  novocain  and 
suprarenin  there  can  be  no  chance  of  a  mistake  occurring  in  the 
amount  of  drug  administered.  The  amount  of  drug  is  exactly 
known,  and  it  is  wise  to  over-  rather  than  underdilute  it.  For 
instance,  a  |  per  cent,  solution  of  novocain  is  better  for  gum  or 
periosteum  infiltration  than  a  i  per  cent,  solution,  although 
some  feel  that  a  i  or  even  2  per  cent,  solution  gives  quicker  and 
better  results  when  used  for  infiltration  around  a  nerve  trunk. 
The  author  uses  the  0.5  per  cent,  solution  wherever  possible, 
and  always  in  frail  or  nephritic  patients,  or  those  having  a 
tendency  to  arteriosclerosis.  In  such  cases  if  an  extra  quantity 
of  the  anesthetizing  solution  is  required,  pure  novocain  can  be 
added  with  the  corresponding  amount  of  Ringer's  solution. 
It  is  particularly  advisable  not  to  increase  the  suprarenin  above 
0.00005  gi^-7  the  amount  contained  in  one  of  the  E  tablets,  for 
even  if  the  entire  amount  of  the  solution  is  given  it  is  only  about 
one-sixth  of  the  generally  accepted  maximum  dose.  Novocain 
has  been  given  in  doses  up  to  i  gram  or  2  grams,  and  there- 


TREATMENT   OF   ROOT   CANALS 


"3 


fore  need  not  be  a  source  of  especial  care,  since  a  twentieth  or 
even  a  thirtieth  of  this  amount  is  seldom  needed  in  any  one  opera- 
tion. This  non-toxicity  of  novocain  is  a  great  blessing,  and  co- 
cain  should  no  longer  be  used  for  local  anesthesia,  for  in  using 
cocain  one  is  handHng  a  drug  of  such  deadly  possibihties  that  one 
never  knows  when  one  will  have  to  fight  desperately  for  the 
life  of  the  patient.  Ordinarily  o.i  or  even  0.5  grain  of  cocain 
will  be  received  hypodermically  with  perfect  complacency, 
but  occasionally  a  patient  will  show  alarming  symptoms  of  col- 
lapse under  ridiculously  minute  doses.  The  author  remembers 
an  extreme  case  where  a  patient  grew  white,  cold,  and  uncon- 


Fig.  40. — Local  anesthetic  syringe.     It  will  hold  e  c.c.     Its  fittings  are  all  metal 
or  glass,  making  complete  sterilization  simple  and  easy. 


scious  from  the  administration  of  0.013  grain  of  cocain,  and 
only  the  promptest  measures  saved  his  life.  Cocain  is  a  veri- 
table tiger  in  the  jungle,  always  ready  to  spring  upon  the  backs 
of  those  compelled  to  use  it.  Novocain  shows  no  such  tendency, 
and  with  ordinary  caution  is  a  perfectly  safe  drug. 

Any  good  sterile  hypodermic  syringe  of  the  type  shown  in 
Fig.  40  may  be  employed.  Platinum  needles  are  preferable 
to  steel,  as  the  latter  rust  and  break  easily.  The  short  needle, 
23  mm.  in  length,  can  be  used  for  ordinary  gum  infiltration, 
while  the  long  needle,  42  mm.  in  length,  is  all  that  is  needed 
for  nerve-blocking,  a  process  which  will  be  described  later. 


114  MODERN  DENTISTRY 

Gum  Infiltration.— Ordinarily  the  pulp  of  any  single-rooted 
tooth  can  be  painlessly  removed  at  the  end  of  five  or  ten  minutes 
after  the  injection  of  0.02  gm.  of  novocain  and  0.00005  S^-  of 
suprarenin  under  the  periosteum  about  the  tip  of  the  root.  The 
point  of  the  needle  should  be  inserted  beneath  the  periosteum 
at  the  labial  aspect  adjacent  to  the  apical  foramen  of  the  root 
to  be  treated,  and  2  c.c.  of  the  solution  slowly  injected.  The 
needle  should  then  be  withdrawn,  and  the  same  procedure 
should  be  carried  out  on  the  lingual  side  of  the  tooth.  This, 
in  a  modified  form,  applies  to  all  of  the  upper  teeth.  In  inject- 
ing the  Hngual  sides  of  the  upper  bicuspids  the  needle  should  be 
inserted  in  the  peridental  membrane  at  the  neck  of  the  tooth, 
since  the  tissues  of  the  palate  in  this  region  are  very  sensitive 
to  the  stab  of  the  needle.  This  same  procedure  also  applies  to 
the  lower  teeth  as  far  back  as  the  first  molar,  but  as  nerve-block- 
ing is  so  wonderfully  effective  in  the  lower  jaw  it  should  always 
be  given  a  trial  before  the  infiltration  method  is  used.  Sometimes 
it  is  necessary  to  supplement  one  with  the  other. 

Nerve-blocking  consists  of  flooding  a  nerve  trunk  with  an 
anesthetic  so  as  to  temporarily  stop  the  passage  of  sensory 
impulses.  The  inferior  dental  nerve  as  it  enters  the  inferior 
dental  canal  on  the  inside  of  the  ramus  of  the  jaw  can  be  flooded 
with  a  solution  containing  0.02  gm.  of  novovain  and  0.00005  g^- 
of  suprarenin,  and  the  lower  jaw  and  lip  on  that  side  rendered 
numb  and  insensitive  for  an  hour  or  two.  At  the  expiration  of 
that  time  the  sensibiHty  of  the  jaw  will  be  restored  to  its  normal 
condition.  If  the  nerve  is  flooded  as  it  comes  out  of  the  mental 
foramen  that  region  of  the  lower  jaw  between  the  second  bicuspid 
and  the  median  fine  will  be  deadened  in  a  similar  manner. 

Nerve-blocking. — The  method  of  nerve-blocking  as  applied 
to  the  inferior  dental  nerve  before  it  enters  the  inferior  dental 
canal  is  as  follows:  The  syringe  should  be  filled  with  2  c.c.  of 
Ringer's  solution  in  which  an  E  tablet  has  been  dissolved.  The 
solution  should  be  blood  temperature  or  a  little  warmer.  The 
syringe  should  be  fitted  with  the  42-mm.  platinum  needle.  The 
gum  should  be  painted  with  iodin  where  the  injection  is  to  be 
made,  and  then  the  finger  of  the  left  hand  should  feel  for  the 


TREATMENT  OF  ROOT  CANALS 


115 


lingual  edge  of  the  inferior  maxillary  ramus  (Figs.  41,  42),  just 
back  of  the  third  molar.  This  edge,  owing  to  the  sudden  widen- 
ing of  the  jaw,  lies  in  a  line  with  the  external  cusps  of  the  molars 
and  is  designated  by  A.  The  ridge  B,  marking  the  outer  surface 
of  the  ramus,  can  be  felt  about  f  inch  exteriorly.  When  the 
inner  edge  has  been  carefully  palpated,  the  point  of  the  hypo- 
dermic needle  should  be  inserted  just  along  the  bone  in  the 
direction  of  the  line  A-C,  outside  of  the  periosteum,  about  | 
inch  above  the  occlusal  line 
of  the  lower  molars.  When 
entrance  has  been  made  and 
the  surface  of  the  ramus  felt, 
the  point  of  the  needle  should 
be  passed  along  the  surface 
of  the  bone  for  about  |  inch, 
curving  as  shown  by  the 
dotted  line,  and  keeping  the 
direction  of  the  puncture  in 
the  occlusal  plane  of  the  lower 
teeth.  At  this  point,  D,  0.2 
c.c.  should  be  slowly  injected 
to  deaden  the  Hngual  nerve. 
At  this  place  the  direction  of 
the  syringe  should  be  changed, 
as  in  the  arc  C-E,  so  that 
finally  the  handle  of  the 
syringe  will  rest  across  the 
junction  of  the  first  bicuspid 

and  canine  on  the  other  side  of  the  jaw.  This  is  necessary 
in  order  that  the  needle  point  may  follow  the  curve  of  the 
ramus.  The  needle  is  then  advanced  in  the  Hne  of  E~F  to 
a  depth  of  0.6  to  0.8  inch  along  the  bone  and  the  remaining 
contents  of  the  syringe  slowly  discharged  at  F.  The  mandibular 
sulcus  containing  the  inferior  dental  nerve  is  shown  by  G.  The 
point  of  the  needle  should  always  lie  away  from  the  bone  rather 
than  toward  it,  and  if  there  is  any  tendency  for  the  needle  to 
jamb  or  stick  it  should  be  withdrawn  slightly  and  advanced  in 


Fig.  41. — Diagrammatic  illustration 
of  directions  and  movements  of  li3rpo- 
dermic  syringe  during  application  of  an- 
esthetizing solution  to  the  trunk  of  in- 
ferior dental  nerve. 


ii6 


MODERN  DENTISTRY 


such  a  manner  that  an  unobstructed  entrance  can  be  obtained. 
At  the  end  of  three  minutes  there  should  be  a  tinghng  and  numb- 
ness of  the  Up,  at  the  end  of  ten  minutes  the  entire  side  of  the 
face  should  have  become  anesthetized.  The  surgical  work  can 
then  be  commenced. 

An  injection  just  posterior  to  the  tip  of  the  first  lower  bicuspid 
will  anesthetize  the  inferior  dental  nerve  as  it  emerges,  while  an 
injection  just  back  of  the  superior  canine  tip  will  have  a  similar 
effect  on  all  of  the  teeth  anterior  to  the  point  of  the  injection. 


Fig.  42. — Lower  jaw,  showing  the  syringe  and  point  of  needle  in  final  position 
when  the  local  anesthetic  is  discharged  for  the  purpose  of  infiltrating  the  inferior 
dental  nerve  as  it  enters  the  inferior  dental  canal. 


In  such  cases  the  short  needle  is  sufficient.  An  injection  high  up 
on  the  maxillary  tuberosity  between  the  second  molar  and  the 
wisdom  tooth  will  also  anesthetize  the  three  upper  molars.  For 
this  the  42-mm.  platinum  needle  is  used.  Those  desiring  fuller 
particulars  on  local  anesthesia  are  referred  to  Fischer  and  Reith- 
mliller's  book,  "Local  Anesthesia  in  Dentistry." 

Valuable  as  infiltration  and  nerve-blocking  are,  they  do  not 
always  prove  successful  in  completely  taking  away  the  sensibility 
of  a  badly  inflamed  pulp  that  is  to  be  removed;  but  where  a 


TREATMENT  OF  ROOT  CANALS 


117 


tooth  is  to  be  extracted,  or  an  alveolus  is  to  be  driUed,  or  a  root 
end  is  to  be  amputated,  the  methods  just  mentioned  are  to  be 
relied  upon.  If,  therefore,  the  pulp  is  very  much  inflamed,  the 
infiltration  method  will  have  to  be  supplemented  by  pressure 
anesthesia,  a  combination  that  gives  very  satisfactory  results. 
Where  the  tooth  is  insensitive  or  quiescent,  and  the  pulp  is 
almost  or  entirely  exposed,  the  local  anesthetization  by  pres- 
sure alone  with  novocain-suprarenin  seems  to  give  the  best 
results.  In  spite  of  every  precaution  there  is  occasionally  pain 
and  soreness  for  an  hour  or  two  after  the  infiltration  or  nerve- 


Fig.  43. — Central  incisor,  showing  pyorrhea  pocket. 

blocking,  while  under  ordinary  conditions  the  pain  occasioned 
by  pressure  anesthesia  is  at  the  time  insignificant  and  usually 
involves  no  after-soreness. 

Pressure  Anesthesia. — The  method  of  forcing  novocam- 
suprarenin  into  the  pulp  of  a  tooth  will  now  be  described.  In 
order  that  the  complete  technic  may  be  given  the  case  presented 
will  be  that  of  a  tooth  where  the  enamel  has  neither  been  injured 
by  a  blow  nor  decalcified  by  decay.  In  such  cases  the  entrance 
to  the  pulp  is  correspondingly  simplified. 

Figure  43  represents  a  single-rooted  tooth.  A  represents  the 
enamel  covering  the  tooth  that  normally  extends  to  the  gum: 


IIJ 


MODERN  DENTISTRY 


B  represents  the  dentin  or  tooth  bone  that  has  been  formed  by 
the  nerve  or  pulp;  C  represents  the  cementum  or  bone-Hke 
structure  that  attaches  the  tooth  to  the  surrounding  peridental 
membrane,  D.  This  membrane  secures  it  to  the  alveolar  process, 
F,  which  is  the  portion  of  the  jaw-bone  that  supports  the  tooth. 
When  the  gum  becomes  infected  by  microbes  the  inflammatory 
exudate  strips  it  away  from  the  root  and  the  intervening  space 
becomes  filled  with  pus  and  tartar,  which  is  diagrammatically 
represented  by  the  dots  G.  E  represents  the  blood-vessels  and 
nerve-fibers  extending  out  from  the  region  around  the  tip  of  the 
root.    There  are  frequently  several  such  openings.    H  represents 


Fig.  44. — ^Labial  aspect 
of  Fig.  43.  Circle  shows 
correct  spot  for  entrance 
of  drill  into  pulp  canal  in- 
dicated by  dotted  lines. 


Fig.  45. — Cross-section         Fig.    46. — Method    of 

of  tooth  where  pulp  has     squeezing  novocain  solu- 

been  just  touched  by  a     tion    into    the    pulp    by 

sharp  drill.  pressure    upon    a  rubber 

plug. 


the  pulp.  As  before  stated,  the  pocket  of  infection  marked  G 
is  one  of  the  common  means  by  which  the  pulp  can  be  infected 
without  any  cavity  of  deca}^  in  the  tooth  itself.  Infection  can 
even  attack  a  pulp  solely  through  germs  floating  in  the  blood. 

Figure  44  represents  the  labiaL aspect  of  the  tooth,  the  circle 
showing  the  spot  where  the  opening  should  be  made  into  the 
pulp  chamber,  which  is  shown  by  the  dotted  Hnes. 

Figure  45  represents  the  cross-section  of  the  same  tooth  show- 
ing the  opening  into  the  pulp.  This  opening  should  be  made  by  a 
sharp,  rapidly  revolving  inverted  cone  bur  large  enough  not  to 
plunge  into  the  nerve.     The  bur  should  just  slice  the  nerve,  an 


TREATMENT  OF  ROOT  CANALS  IIQ 

operation  which  can  be  done  with  very  Httle  pain  to  the  patient. 
When  the  exposure  of  the  pulp  has  been  completed,  one  or  two 
crystals  of  novocain  wet  with  a  little  adrenahn,  or  about  one- 
quarter  of  an  E  tablet  powdered  and  moistened  with  water, 
should  be  placed  in  the  cavity  in  direct  contact  with  the  exposed 
pulp.  A  pellet  of  soft  un vulcanized  rubber  is  then  placed  in  the 
orifice  of  the  tooth,  and  firm  pressure  is  made  upon  it  with  any 
blunt  instrument  (Fig.  46)  so  that  the  rubber  shall  be  driven 
well  into  the  cavity,  thus  driving  the  novocain  into  the  substance 
of  the  pulp.  This  will  be  a  painful  procedure  in  direct  proportion 
as  the  circulation  in  the  pulp  has  been  destroyed  by  infection. 
If  there  is  fairly  good  circulation  in  the  pulp,  the  slightest  pres- 
sure will  squeeze  in  sufficient  of  the  local  anesthetic  to  completely 
deaden  sensibility,  inasmuch  as  any  quantity  that  is  forced  in 
will  be  immediately  distributed  by  the  blood  circulation  through- 
out the  entire  pulp  substance.  If,  however,  the  circulation  is 
entirely  lacking  through  excessive  congestion  or  calcic  infiltration, 
the  local  anesthetic  must  be  forced  into  the  pulp  by  pressure 
alone,  and  this  causes  much  more  pain.  In  general  practice  it  is, 
therefore,  wise  under  the  conditions  stated  to  give  a  firm,  sharp 
punch  on  the  rubber  and  maintain  the  pressure.  Ordinarily  there 
will  be  practically  no  pain,  and  if  there  is  excessive  congestion 
and  pain  cannot  be  avoided,  the  sooner  it  is  over  the  better.  In 
extreme  cases  if  the  pulp  can  only  be  anesthetized  for  a  short 
distance,  and  there  proves  to  be  great  sensibihty  underneath, 
the  point  of  a  hypodermic  needle  may  be  inserted  into  the  dead- 
ened area  of  the  pulp  and  the  rest  of  the  pulp  injected  with  the 
anesthetic.  This  can  usually  be  accomplished  with  very  Httle 
pain,  as  the  injection  opens  up  the  congested  blood-vessels  which 
the  pressure  alone  had  tended  to  compress.  Before  insertion,  the 
point  of  the  h3^odermic  needle  should  be  ground  off  to  an  angle 
of  45  degrees,  as  the  ordinary  long  point  would  necessarily  run 
well  into  the  sensitive  area,  which  w^ould,  of  course,  defeat  the 
entire  purpose  of  the  procedure. 

There  are  two  objections  that  can  be  raised  against  this 
method  of  pulp  anesthesia:  first,  the  pain,  which,  however,  is 
not  ordinarily  more  than  passing  discomfort;  second,  the  possi- 


I20  MODERN   DENTISTRY 

bility  of  forcing  infection  through  the  tip  of  the  root.  The  danger 
of  spreading  infection  through  the  tip  is  ordinarily  negligible, 
as  infected  pulps  in  a  large  percentage  of  cases  have  partly 
infected  the  area  just  outside  the  tip  of  the  root  by  which  a 
certain  toleration  may  already  have  been  established,  and  any 
infection  forced  out  by  the  procedure  just  described  will  readily 
be  taken  care  of  by  the  blood-serum  in  the  peridental  membrane. 
At  least  that  has  been  the  author's  experience.  Of  course,  if  a 
thoroughly  putrescent  pulp  is  subjected  to  this  procedure,  enough 
infection  may  be  forced  out  to  cause  an  abscess,  the  bacterial 
resistance  of  the  parts  being  overwhelmed.  But  even  in  such  a 
case  it  is  astonishing  how  much  infection  the  tissues  at  the 
tips  of  infected  roots  can  accept  without  forming  an  acute  ab- 
scess. If,  however,  an  acute  abscess  does  start,  an  aqueous  2 
per  cent,  solution  of  carboHc  acid  should  be  forced  through  the 
tip  of  the  root  after  the  pulp  has  been  removed,  and  if  this  fails 
to  control  the  inflammation,  the  gum  on  the  outside,  opposite 
the  tip,  should  be  at  once  injected  with  novocain  and  an  opening 
made  through  the  alveolar  plate  so  as  to  relieve  the  inflamma- 
tory pressure.  This  is  a  sure  means  of  aborting  an  abscess. 
However,  as  before  stated,  when  there  is  reason  to  suspect  great 
resistance  to  the  entrance  of  novocain,  or  a  spreading  of  infection 
from  pressure  through  the  root  foramen,  the  method  described 
for  injecting  the  periosteum  at  the  tip  of  the  tooth  is  to  be  pre- 
ferred. In  fact,  if  there  is  resistance  to  anesthesia  by  pressure, 
the  infiltration  or  nerve-blocking  method  should  be  used  as  an 
auxiliary  assistance. 

Removal  of  the  Dental  Pulp. — When  the  pulp  has  been 
deadened  we  have  usually  about  half  an  hour  to  remove  it  be- 
fore it  regains  sensibility.  A  bur  should  thoroughly  cut  away 
the  bony  covering  of  the  pulp,  and  then  a  fine  piano-wire  engine 
drill  should  be  plunged  to  the  bottom  of  the  canal  until  it  jams 
(Fig.  47).  This  will  cut  off  the  circulation  and  nerve  connection 
with  the  tissues  outside  of  the  tooth,  and  will  make  it  possible, 
by  gradually  using  larger  and  larger  drills,  to  thoroughly  excavate 
not  only  the  pulp  itself  but  a  large  percentage  of  the  decompos- 
able tissue  in  the  dentin,  since  the  dentin  lying  next  to  the  pulp 


TREATMENT  OF  ROOT  CANALS 


121 


contains  by  far  the  greatest  proportion  of  organic  tissue.  If, 
therefore,  the  canal  is  enlarged  well  into  the  surrounding  dentin, 
about  nine-tenths  of  all  the  soft  organic  material  will  have  been 
removed  from  the  tooth  bone,  and  consequently  there  will  be 
just  so  much  less  risk  of  later  decomposition  and  discoloration 
(Fig.  48). 

The  greatest  advantage  of  anesthesia  over  the  old  arsenic 
method  of  devitalization  lies  in  the  fact  that  with  novocain 
anesthesia  the  dentin  is  not  killed,  and  can  be  still  nourished  by 
the  peridental  membrane  through  the  cells  of  the  cementum 
and  the  interglobular  spaces.    After  pulps  have  been  removed 


Fig.  47. — Showing  the  use  of  a  fine 
canal  drill  in  cutting  off  the  tip  of  the 
pulp  at  the  apical  foramen. 


Fig.  48. — Diagram  of  a  tj^pical 
single-rooted  tooth  with  pulp  canal 
reamed  out  for  filling. 


by  such  anesthesia  in  some  rare  cases  sensibility  of  the  dentin  to 
the  touch  has  been  noticeable  for  a  year  or  two.  Such  nerve 
sensations  could  only  have  come  by  way  of  the  cementum  and 
interglobular  spaces.  It  is  true  that  not  over  5  or  6  undoubted 
cases  of  such  a  character  have  come  to  my  notice  during  the  last 
twenty-five  years,  but  these  are  sufficient  to  convince  me  that  a 
tooth  without  its  pulp  may  be  a  living  tooth  nourished  in  all 
parts. 

Tooth  Nutrition  by  the  Peridental  Membrane. — Recent 
experiments  on  guinea-pigs  by  Dr.  Gies,  of  Columbia  University, 
show  that  a  blue  dye,  injected  into  the  abdomen  of  a  guinea-pig, 
in  a  few  days  will  be  found  to  have  stained  the  entire  substance 


122  MODERN  DENTISTRY 

of  the  teeth  blue — enamel,  cementum,  dentin,  pulp,  peridental 
membrane,  and  gum.  The  saliva  did  not  show  the  stain,  so  the 
enamel  must  have  been  stained  from  within  through  the  dentin. 
This  even  occurred,  although  to  a  lesser  degree,  when  the  pulp 
was  removed,  which  would  seem  to  indicate  that  even  the 
enamel  can  be  reached  by  the  blood-serum  through  the  peri- 
dental membrane,  cementum,  and  dentin.  Further  experiments 
on  this  subject  are  in  progress. 

The  author  emphasizes  the  possibility  of  a  tooth  deprived  of 
its  pulp  being  nourished,  and  he  deplores  the  general  tendency 
to  call  such  a  tooth  dead.  If  a  tooth  becomes  infected  it  may  lose 
all  gum  attachments  and  die,  but  a  tooth  deprived  of  its  pulp 
may  still  contain  hving  cementum,  dentin,  and  enamel,  all  of 
which  can  be  nourished  by  the  healthy  peridental  membrane. 
Such  a  tooth  is  very  much  alive,  and  should  not  be  looked  upon 
as  dead,  but  as  a  living  member,  capable  of  performing  its 
valuable  functions. 

The  anesthesia  method,  since  it  allows  any  remaining  pulp 
to  regain  sensibihty,  makes  it  possible  to  discover  and  properly 
treat  minute  canals  that  otherwise  might  have  been  overlooked 
if  the  tissue  had  been  permanently  destroyed  by  arsenic.  This 
is  particularly  the  case  with  multiple-rooted  teeth,  which  point 
will  be  dwelt  upon  later. 

Root  Canal  Preparation. — The  pulp  having  been  removed 
from  the  canal  and  the  canal  enlarged,  the  pulp  chamber  should 
then  be  as  carefully  sterilized  as  though  the  removed  pulp  had 
been  putrescent.  The  failure  to  do  this  will  cause  an  abscess 
that  otherwise  would  not  occur. 

The  Beutelrock  drills,  as  shown  in  Fig.  49,  are  invaluable, 
especially  where  the  canal  is  extremely  small.  Care  should  be 
taken  to  use  the  smallest  drill  first,  and  then  follow  up  with  the 
next  size,  until  the  canal  is  as  large  as  desired.  If  the  larger  drills 
are  used  first,  followed  by  the  smaller,  the  point  of  the  drill  may 
become  deviated  from  the  true  course  of  the  canal,  and  an  open- 
ing made  in  the  side  of  the  root,  as  in  Fig.  50.  Experience  will 
teach  the  student  that  all  root  canals  are  not  as  large  or  self- 
evident  as  the  canals  shown  in  most  of  the  published  diagrams. 


TREATMENT  OF   ROOT   CANALS 


123 


W 


(nz^n;. 


az3^ 


(IZ3:G 


(EJQ 


(C^ 


(TJG 


e::^ 


n:^ 


CjE 


0= 


CZE 


CE 


They  are  very  often  infinitesimal,  and  show  such  incalculable 
variations,  from  large  to  minute  diameters,  that  only  the  greatest 
care  can  give  consistently  good  results. 


124 


MODERN  DENTISTRY 


Sets  of  valuable  reamers  and  broaches  are  shown  in  Figs. 
51  to  53. 

Sterilization  and  Root  Canal  Filling. — The  methods  recom- 
mended for  sterihzing  the  canal  after  the  pulp  has  been  re- 
moved are  so  numerous  that  only  one  or  two  will  be  described. 
When  the  canal  has  been  opened  and  mechanically  cleansed  of 
its  pulp  a  drop  of  half  formahn  and  half  tricresol,  freshly  mixed 
for  each  treatment,  is  flowed  in.  A  small  plug  of  cotton  is  then 
inserted  and  the  orifice  dried  and  sealed  with  a  covering  of  soft 
phosphate  of  zinc  cement.  This  forma- 
lin-tricresol  antiseptic  mixture  was  first 
recommended  by  Buckley.  It  is  ex- 
tremely effective,  especially  if  used  with 
a  cement  seal,  as  the  heat  of  the  body 
causes  formaldehyd  gas  to  be  liberated 
and  driven  through  all  parts  of  the 
tooth,  and  even  through  the  tip  into  the 
adjacent  parts,  causing  a  complete  dis- 
infection and  deodorization  of  the  tooth 
without  discoloration.  The  author  finds 
it  better  to  mix  formalin  and  tricresol 
fresh  each  time,  as  it  has  been  his  expe- 
rience that  the  formahn  and  tricresol 
when  mixed  together  in  stock  solution 
tend  to  discolor  the  tooth.  When 
there  is  sensibiHty  at  the  tip  after  the 
pulp  has  been  removed,  it  is  wise  to 
allow  the  dressing  to  remain  until  such  sensibility  to  pressure  or 
mastication  has  completely  disappeared,  even  it  if  takes  two  or 
three  weeks.  Within  a  week  of  the  time  that  the  final  root-canal 
filhng  is  to  be  inserted,  the  tooth  should  be  opened  and  again 
treated  with  the  formahn  mixture  in  the  same  way.  If  the  second 
treatment  is  accepted  without  sensibility  developing  during 
the  first  twenty-four  hours,  and  all  odor  of  putrescence  is  absent, 
the  tooth  should  be  filled  as  follows:  A  napkin,  cotton  roll,  or 
a  dam  should  be  appHed  and  the  tooth  dried  with  a  warm  air- 
blast,  great  care  being  taken  to  see  that  the  canals  are  free  from 


Fig.  50. — Diagram  of 
an  accident  caused  by  using 
a  large  rigid  drill  to  open 
the  canal.  The  smaller 
drill  found  the  pocket  in 
the  side  of  the  canal  and 
made  a  false  opening  at  a 
instead  of  cleansing  the 
true  opening  at  the  apical 
foramen. 


TREATMENT  OF  ROOT  CANALS 


125 


moisture.     Then  thick,  syrupy  chlora-percha  should  he  gently 
flowed  to  the  tip  of  the  canal  and  suitable  gutta-percha  cones 


Fig.  51. — Barbed  piano- 
wire  broach,  originally  called 
the  Donaldson  nerve  broach. 


Fig.  52. — Kerr  tapered  canal  reamers. 


I\ 


H       d 


Fig-  S3- — Gates-Glidden  drills. 


inserted,  and  with  a  pumping  motion  gently  worked  as  far  into 
the  canal  as  possible,  care  being  taken  not  to  force  the  liquid 
gutta-percha  beyond  the  foramen. 


126  MODERN  DENTISTRY 

But  when  there  is  the  sHghtest  danger  of  forcing  the  liquid 
gutta-percha  through  the  tip  of  the  root  it  is  advisable  to  fill 
the  canal  with  eucalyptus  oil  and  then  insert  a  gutta-percha  cone. 
When  this  has  been  allowed  to  remain  in  position  for  a  minute 
it  can  be  forced  up  into  position  near  the  canal  foramen  and  the 
interstices  will  be  filled  with  the  gutta-percha  dissolved  in  the  oil. 
With  this  method  there  is  the  minimum  danger  of  forcing  the 
gutta-percha  beyond  the  root  canal,  and  therefore  it  is  frequently 
to  be  preferred,  as  it  is  better  to  only  partially  fill  a  steriHzed 
canal  than  to  project  the  filling  through  the  tip.  The  principal 
thing  to  remember  is  that  the  canal  must  be  sterile  when  it  is 
filled.  When  this  procedure  has  been  carried  out  the  gutta- 
percha should  be  packed  into  place  with  a  warm  instrument 
and  the  exterior  opening  filled  either  with  silicious  cement,  gutta- 
percha, or  any  other  filling  material  that  seems  appropriate. 
When  the  pulp  is  dead  and  putrescent  it  is  always  wise  to  place 
a  drop  of  the  formalin-tricresol  mixture  within  the  tooth  and  seal 
it  up  with  cement  for  at  least  twenty-four  hours  prior  to  working 
on  the  root  canal  or  canals.  This  must  not  be  done  if  the  tooth  is 
sensitive  to  pressure  or  the  peridental  membrane  is  actively 
inflamed.  To  do  this  will  increase  the  trouble  by  imposing  the 
expanding  gas  on  the  infected,  irritated  tissues.  When  there  is 
sensibility  to  pressure,  indicating  the  incipient  formation  of  an 
abscess,  a  tooth  should  merely  be  opened  with  a  drill  and  appli- 
cations of  iodin  made  to  the  surrounding  gum.  In  a  large  major- 
ity of  such  cases  the  inflammation  will  subside  in  a  few  days 
to  the  point  where  the  antiseptic  mixture  will  be  easily  borne, 
and  the  procedure  just  described  can  be  carried  out.  No  root 
canal  should  ever  be  sealed  up  permanently  so  long  as  there  is 
the  slightest  odor  of  putrescence.  The  application  of  formalin  and 
tricresol  will  always  be  effective  in  removing  such  a  condition. 

Calahan  Method. — When  the  root  canal  is  very  difficult  to 
find,  50  per  cent,  aqueous  sulphuric  acid  should  be  apphed,  and, 
if  possible,  sealed  within  the  pulp  chamber.  On  the  following 
day  the  root  canal  will  be  shown  by  a  small  softened  discolored 
spot,  while  the  surrounding  dentin  or  tooth  bone  will  be  white 
and  clean.    If,  however,  there  is  sensibility  at  the  tip  of  the  root 


TREATMENT  OF  ROOT  CANALS  1 27 

the  pressure  of  the  carbon  dioxid  liberated  by  the  action  of  the 
sulphuric  acid  on  the  carbonate  of  calcium  in  the  tooth  will  be 
too  great  to  permit  seahng  the  acid  within  the  cavity.  Under 
these  circumstances  it  is  sometimes  of  value  to  work  the  acid 
into  the  pulp  chamber  with  a  small  piano-wire  probe,  afterward 
washing  out  the  free  acid  with  a  bicarbonate  of  soda  solution. 
This  will  ordinarily  disclose  the  location  of  the  root  canal, 
which  can  then  be  treated  in  the  usual  way.  It  will  be  noted 
that  it  is  recommended  to  work  up  into  the  root  canal  as  far  as 
possible,  because  it  is  not  always  possible  to  fill  all  the  fine  root 
canals  to  the  tip.  In  fact,  the  root  canals  frequently  have  three 
or  four  openings  on  the  root,  some  at  the  tip  and  some  at  the 
side,  and  those  who  claim  that  they  always  fill  all  the  root  canals 
to  the  tip  prove  themselves  by  such  a  statement  ignorant  of 
the  difficulties  to  be  encountered.  Frequently  when  the  pulp 
canal  has  become  infiltrated  with  Hme  salts,  observation  will 
not  locate  it.  Under  these  conditions  a  fine,  sharp  piano-wire 
explorer  should  be  dug  into  the  dentin  all  over  the  floor  of  the 
pulp  chamber,  and  this,  in  many  instances,  will  locate  the  pulp 
canal  that  otherwise  would  be  completely  masked  by  the  white, 
soft,  calcic  infiltration.  Such  an  opening  can  then  be  entered  by 
a  thin  piano-wire  drill.  If,  as  before  stated,  the  sensibility  at 
the  tip  will  not  allow  the  formalin-tricresol  mixture  to  be  sealed 
within  the  tooth,  it  may  be  left  open,  protected  only  with  a  Hght 
padding  of  carbolic  acid  and  cotton.  Sometimes  when  the  bac- 
terial resistance  of  the  patient  is  so  low  that  it  seems  impossible 
to  close  the  tooth  without  causing  the  chronic  inflammation  at 
the  apex  of  the  root  to  become  acute,  it  will  be  found  good  practice 
to  seal  carboHc  acid  or  tricresol  and  cotton  in  the  root  canal 
with  cement,  and  then  to  immediately  make  an  opening  in  the 
side  of  the  tooth  with  a  small  drill  into  the  pulp  chamber  to 
eliminate  the  possibiUty  of  gas  pressure  (Fig.  54).  This  will 
obviate  any  lack  of  drainage  and  wiU  enable  the  tooth  to  slowly 
recuperate.  Such  an  opening  should  always  be  made  when 
acute  sensibility  of  the  tip  makes  it  advisable  to  eliminate  gas 
pressure.  If,  as  sometimes  happens,  the  inflammation  persists 
in  spite  of  this  vent,  and  counter-irritation  on  the  gum  is  unavail- 


128 


MODERN  DENTISTRY 


ing,  electrolysis  with  the  negative  pole  of  a  dry  cell  battery  in 
series  will  be  valuable  in  allaying  the  pain,  as  is  described  in 
Chapter  III.  If  this  does  not  prove  completely  effective,  an 
opening  should  be  made  through  the  side  of  the  alveolar  plate, 
exposing  the  tip  of  the  root.  The  opening  at  the  tip  of  the  root 
should  be  enlarged  if  necessary,  and  the  root  filled  thoroughly 
through  the  tip.  The  root  tip  with  the  protruding  gutta-percha 
should  be  smoothed  with  a  bur.  At  the  same  time  any  bone 
found  in  the  alveolar  plate  lacking  its  full  vitality  should  be 
thoroughly  bored  away.  This  process 
will  be  more  fully  described  later  in  the 
chapter. 

Emetin. — When  a  root  canal  has  been 
filled  with  gutta-percha  and  a  sensibility 
develops,  I  grain  of  emetin  hydrochlorid, 
injected  intramuscularly  four  or  five 
days  in  succession,  will  often  be  of  great 
service  in  allaying  the  symptoms.  The 
patient  should  also  be  required  to  take 
I  ounce  of  epsom  salts.  This  latter  by 
depleting  the  blood-serum  will  greatly 
assist  in  reducing  any  inflammatory 
tendency,  while  the  emetin,  possibly  by 
sensitizing  the  germs  at  the  tip  of  the 
inflamed  root,  will  enable  the  blood- 
serum  to  more  readily  dispose  of  them.  I  mention  this 
possibility  because  I  think  it  a  more  probable  theory  than 
the  supposition  that  the  ameba  could  be  responsible  for  such 
inflammatory  areas,  since  such  areas  are  usually  cut  off  from  the 
mouth,  and  it  does  not  seem  credible  that  the  ameba  could  reach 
them  through  the  blood-stream.  It  is  also  good  practice  to  give 
calomel  where  there  is  an  inflammatory  tendency,  as  the  hver 
is  much  more  efficient  in  combating  infection  when  it  has  been 
relieved  of  any  engorgement  that  is  likely  to  exist  under  such 
conditions. 

Canal  Variations. — In  dealing  with  single-rooted  teeth  one 
sometimes  finds  that  there  are  two  or  even  three  canals  that 


Fig.  54. — A,  Cement 
seal;  B,  cotton  antiseptic 
dressing;  C,  vent  which  al- 
lows drainage  or  the  escape 
of  gas  that  may  not  be  en_ 
dured  by  the  inflamed  tip. 


TREATMENT  OF  ROOT  CANALS 


129 


should  be  opened  and  mechanically  cleansed.  It  sometimes 
happens  that  the  root  without  any  warning  will  curve  sharply, 
forming  a  complete  right  angle,  as  in  Fig.  55.  Such  a  condition 
makes  it  all  but  impossible  not  to  perforate  the  tooth  at  A  in  an 
attempt  to  cleanse  the  canal,  and  makes  it  mechanically  quite 
out  of  the  question  to  cleanse  the  canal  beyond  the  sharp  angle. 
Where  it  is  possible  to  diagnose  such  a  condition  with  the  a;-ray, 
some  dentists  recommend  seaKng  up  sul- 
phuric acid  in  the  tooth.  This  is  sup- 
posed to  burn  the  pulp  sufficiently  to 
permit  of  its  being  washed  out  with  a 
solution  of  carbonate  of  soda,  and  the 
canal  can  then  be  filled  with  hquid 
gutta-percha  or  oxyphosphate  of  zinc. 
This  procedure  is  more  theoretically 
than  practically  possible.  There  is  al- 
ways the  possibihty  that  such  a  distor- 
tion exists,  and  there  is  absolutely  no 
means  but  the  x-ray  for  diagosing  such 
a  condition.  It  almost  invariably  hap- 
pens, however,  that  under  such  con- 
ditions   an    apical    abscess    eventually 

develops  and,  therefore,  if  a  tooth  does  not  heal  properly  the 
x-ray  should  always  be  used,  and  will  be  an  invaluable  guide 
for  operative  procedure. 

If  this  is  so  concerning  single-rooted  teeth,  how  much  more 
so  is  it  with  multiple-rooted  teeth  showing  abnormalities!  One 
such  case  was  that  of  an  upper  second  bicuspid  that  had  three 
roots  when  there  is  ordinarily  but  one,  and  three  root  canals, 
only  one  of  which  canals  was  found  and  filled.  Before  the  days 
of  x-rays  how  many  such  anomalies  have  escaped  me  and  have 
spread  infection,  the  shade  of  ^sculapius  only  knows.  Another 
case  was  that  of  an  upper  central  incisor  that  had  two  roots  and 
two  canals.  The  unfilled  canal  naturally  continued  to  spread 
infection  and  the  tooth  eventually  had  to  be  extracted.  When 
we  consider  molars  any  one  of  which  may  have  only  one  large 
canal,  bifurcated  or  not  bifurcated,  or  may,  by  chance,  have 
9 


Fig-  55- — Diagrammat- 
ic illustration  of  a  not  infre- 
quent condition  at  the  tip 
of  a  root. 


130  MODERN  DENTISTRY 

four,  five,  or  six  canals,  the  man  who  says  that  in  every  instance 
he  finds  and  fills  all  of  these  canals  to  the  tips  of  the  roots  is  so 
optimistic  that  he  makes  himself  ridiculous.  This  same  man, 
who  claims  to  have  such  perfect  technic  in  filling  root  canals, 
almost  invariably  claims  that  he  never  breaks  off  a  probe  or 
root  canal  drill  during  the  process  of  canal  excavation.  Such 
an  accident,  though  lamentable  and  to  be  avoided,  will  occur  to 
the  most  skilful,  and  the  man  who  never  runs  the  risk  of  breaking 
off  a  delicate  drill  in  a  canal,  of  necessity,  has  not  the  courage  to 
properly  cleanse  the  canals.  Our  dental  technic  is  too  good  and 
skilful  to  require  evasions  or  mendacity  as  a  protection.  Better 
by  far  that  the  very  occasional  tip  of  a  root  should  be  amputated, 
or  even  a  tooth  extracted,  than  to  condemn  all  teeth  to  a  probable 
danger  of  infection  through  timidity  in  canal  cleansing.  The 
conscientious,  frank  dentist  knows  his  unavoidable  percentage 
of  failures;  he  can  only  reduce  the  failures  to  a  minimum  by 
realizing  and  appreciating  them,  not  by  denying  and  ignoring 
them.  He  knows  that  central  and  lateral  incisors  and  canines, 
upper  and  lower,  nine  hundred  and  ninety-nine  times  out  of  a 
thousand,  have  only  one  root  canal,  which  is  usually  straight 
and  can  be  successfully  filled  to  the  tip.  He  knows  that  the 
upper  first  bicuspid  ordinarily  has  two  canals,  and  these  two 
canals  can  ordinarily  be  successfully  filled.  The  upper  second 
bicuspid  and  the  lower  first  and  second  bicuspids  ordinarily  have 
one  canal.  Any  of  these  teeth  may  have  additional  roots  and 
canals,  and  any  of  these  canals  may  turn  suddenly,  making 
complete  filKng  impossible,  and  yet  the  dentist  can  only  use 
judicious  cutting  and  caution.  To  do  otherwise  would  mean 
an  incalculable  waste  of  tooth  structure  and  time.  It  would 
mean  a  great  increase  in  the  openings  made  through  the  sides  of 
root  canals  into  the  gum;  for  when  the  root  canals  have  been 
properly  reamed  out  all  extra  cutting  merely  weakens  the  tooth 
and  increases  the  danger  of  puncturing  the  cementum.  In  the 
same  way  the  dentist  knows  that  the  upper  and  lower  first 
molars  ordinarily  have  three  canals,  but  they  may  have  only 
one  or  two,  or  they  may  have  four  or  five.  He  is  between  Scylla 
and  Charybdis;  if  there  is  only  one  and  he  hunts  for  more,  he 


TREATMENT  OP   ROOT  CANALS  I. 3 1 

uselessly  sacrifices  the  tooth.  If  he  finds  three  and  thoroughness 
makes  him  rashly  hunt  for  more,  for  the  one  time  he  succeeds 
in  finding  the  canal  he  has  a  hundred  failures,  and,  in  reality, 
the  fine  hair-like  canals  ordinarily  do  not  cause  irritation  that 
the  peridental  membrane  cannot  control.  In  exploring  for  root 
canals  the  dentist  cannot  do  better  than  follow  the  technic  of 
Flagg  and  his  successors,  which  is  about  as  follows :  When  a  tooth 
is  opened  into  the  pulp  chamber  the  roof  of  the  pulp  chamber 
should  be  completely  removed  and  the  floor  burred  until  the 
body  of  the  nerve  is  completely  removed  and  the  canal  or  canals 
are  in  plain  view.  Then  at  least  he  should  use  every  effort 
to  find  all  the  canals  that  are  ordinarily  present.  With  single- 
rooted  teeth  there  must  be  one  canal  at  least;  in  reason,  let  him 
look  carefully  for  more.  Sometimes  he  wiU  not  be  able  to  find 
even  that  one.  In  bicuspids  it  should  be  remembered  that  two 
canals  are  not  uncommon,  and  he  should  see  to  it  that  the  floor 
of  the  pulp  chamber  is  thoroughly  exposed,  cleansed,  and  explored. 
After  that  let  him  fill  the  canals  that  are  found  and  leave  the 
rest.  With  the  molars  he  should  cut  freely  and  thoroughly  to 
expose  to  view  the  floor  of  the  pulp  chamber.  With  first  molars 
let  him  expect  three  canals,  and  not  be  nonplussed  if  he  finds 
four  or  five;  neither  let  him  condemn  himself  too  harshly  if  care- 
ful exploration  reveals  only  one  or  two,  lest  by  too  thorough 
searching  he  perforates  the  side  of  the  canal  into  the  gum  outside 
and  thus  finds  a  few  that  do  not  exist.  With  second  molars 
three  canals  are  the  rule,  although  they  are  often  difficult  to 
demonstrate.  With  third  molars  it  is  to  be  remembered  that  there 
may  be  one  canal  the  size  of  a  stick  of  Itahan  spaghetti,  or  there 
may  be  four,  five,  six,  or  seven  of  a  hair-Hke  quahty,  to  dis- 
cover which  would  require  the  "milHon  magnifier  eyes"  so  elo- 
quently disclaimed  by  Mr.  Samuel  WeUer.  With  some  of  these 
the  skiagraph  will  only  show  that  the  tips  have  not  been  reached 
and  will  not  reveal  whether  bone  infection  is  or  is  not  going  to 
develop.  If  such  infection  should  develop  it  will  not  be  shown 
by  the  x-ray  plate  until  six  months  or  a  year  has  passed.  All 
the  dentist  can  do  is  in  every  instance  to  follow  the  rules  and  do 


132  MODERN   DENTISTRY 

his  best,  and  not  bore  his  fellow-workers  with  claims  of  perfection 
in  technic. 

In  filHng  large,  obvious  canals  it  is  wise  to  use  oil  of  eucalyp- 
tus and  a  cone  of  gutta-percha.  Oil  of  eucalyptus  should  be 
pumped  in  first,  then  the  gutta-percha  cone  inserted  and  worked 
slowly  up  and  down  until  it  settles  as  near  the  bottom  of  the 
canal  as  possible.  It  should  be  allowed  to  soak  up  the  excess 
eucal3^tus  for  a  minute  or  two,  and  then  with  a  hot  instrument 
pushed  home  and  more  gutta-percha  added  until  the  canal  is 
fiUed.  And  each  time  the  conscientious  dentist  does  this,  he 
prays  that  it  has  filled  the  canal  to  the  cementum,  and  also  that 
neither  the  cone  nor  the  liquid  gutta-percha  has  been  forced 
through  the  tip.  The  cementum  being  actively  aHve  will  fre- 
quently satisfactorily  close  up  an  aseptic  apical  foramen  if  the 
gutta-percha  does  not  extend  beyond  it  into  the  soft  tissues. 
The  only  way  to  be  certain  that  the  root  canal  is  completely 
filled  is  to  boldly  push  the  gutta-percha  through  the  tip,  and  then 
to  smooth  it  off  with  a  bur  by  going  through  the  alveolus  from 
the  outside  of  the  gum.  The  method  of  preparing  and  filling 
root  canals  just  described  almost  invariably  gives  good  cHnical 
results,  but  when  it  fails  and  chronic  inflammation  at  a  root  tip 
shows  that  the  gutta-percha  filling  is  not  acting  as  a  satisfactory 
protection,  the  tip  should  be  excised  or  the  root  extracted. 
With  the  smaller,  thread-like  canals  thin  oxyphosphate  of  zinc 
makes  an  excellent  filling,  since  it  can  readily  be  pumped  into 
place  with  a  hair-like  broach,  and  if  a  little  excess  does  escape 
through  the  root  the  excess  is  absorbed,  although  not  without 
some  pain.  However,  when  the  pain  goes,  there  is  seldom  any 
bad  after-result.  When  there  is  a  distinct  tendency  for  irritation 
to  persist  at  the  tips  of  the  roots  a  very  small  portion  of  iodoform 
can  be  placed  at  the  tip  before  the  gutta-percha  is  inserted. 
Great  caution  should  be  observed  in  using  iodoform  in  a  front 
tooth,  as  when  used  in  any  quantity  it  causes  a  stain  to  develop 
that  it  is  practically  impossible  to  remove.  Paraffin  and  other 
similar  semiliquid  materials  have  been  used  for  filling  root 
canals,  but  they  are  apt  to  be  absorbed,  leaving  the  canals 
unprotected. 


TREATMENT  OF  ROOT  CANALS  133 

Bleaching. — Before  we  leave  the  subject  of  root  canal  steril- 
ization and  filling  it  must  not  be  forgotten  that  tooth  discolor- 
ation may  enter  as  a  factor  of  considerable  importance.  This 
discoloration  has  to  be  \iewed  both  from  the  hygienic  as  well  as 
the  cosmetic  point  of  view.  Tooth  discoloration  may  come  from 
purely  chemical  causes,  such  as  amalgam  salts,  nitrate  of  silver, 
iodoform,  or  any  of  the  essential  oils  commonly  used  in  the  treat- 
ment of  root  canals,  or  the  discoloration  may  be  due  to  pulp 
deterioration.  This  latter  discoloration  appears  first  as  a  faint 
yellow  cloudiness,  and  as  the  pulp  further  loses  its  vitahty  and 
finally  dies,  this  cloudiness  may  progressively  change  to  a  dark 
brown  or  a  grayish  black. 

Discolorations  due  to  a  chemical  or  purely  mechanical  cause, 
while  distressing,  are  not  a  pathologic  danger  sign;  but  discol- 
orations caused  by  pulp  infection  and  infiltration  into  the  tooth 
substance  are  not  only  unsightly,  but  a  menace  to  the  general 
health  of  the  patient.    And  yet  it  is  not  always  an  easy  matter  to 
decide  which  type  of  discoloration  is  presented  to  us.    It  may  be 
a  combination  wherein  the  tooth  has  started  to  discolor  through 
pulp  deterioration,  and  has  been  assisted  along  its  uncosmetic 
path  by  pulp-canal  dressings  such  as  iodoform  or  oil  of  cloves. 
Such  chemical  discolorations  cannot  be  bleached  by  any  known 
materials.    When  such  a  discoloration  occurs  the  best  bleacher 
is  the  bur  or  stone  that  cuts  out  the  discolored  tooth  substance 
and  makes  room  for  a  suitable  porcelain  or  cement  restoration. 
But  where  there  is  the  possibility  that  the  discoloration  may 
also  arise  from  previous  pulp  decomposition  and  infiltration 
throughout  the  tooth,  the  root  canals  should  be  carefully  treated 
and  the  tips  filled  as  just  described.     Thorough  attempts  at 
bleaching   should   then   be   inaugurated,   whether   they  prove 
successful  or  not,  for  the  process  of  restoring  the  natural  color 
to  a  tooth  discolored  by  pulp  infection  is  accomplished  by  act- 
ually oxidizing  and  destroying  the  putrescent  substance  of  the 
pulp  that  has  permeated  the  tooth;  and  therefore,  even  if  the 
bleaching  process  is  not  able  to  remove  the  chemical  stain,  it  is 
nevertheless  hygienically  of  the  utmost  value.    For  if  the  crown 
of  a  tooth  blackened  by  the  infiltration  of  pulp  infection  is  merely 


134  MODERN  DENTISTRY 

cut  off  and  replaced  by  a  suitable  porcelain  substitute,  the 
infection  in  the  root  may  and  probably  will  continue  to  grow, 
because  all  the  germ  food  on  which  the  infection  could  subsist 
is  still  present,  ready  for  the  nourishment  of  any  stray  germs  that 
may  possibly  have  escaped  the  antiseptics,  or  may  later  obtain 
entrance  through  a  defectively  filled  apical  foramen. 

Therefore,  tooth  discolorations  that  arise  from  the  death  of 
the  pulp  and  the  infiltration  of  the  infected  mass  into  the  inter- 
stices of  the  tooth  should  not  be  tolerated.  This  discoloration 
is  not  merely  unsightly,  it  is  a  source  of  deterioration  that  in 
time  will  actually  undermine  the  stability  and  usefulness  of  the 
tooth,  and  the  dentist  who  does  not  appreciate  the  danger  is 
probably  not  thorough  in  his  steriHzation,  and  thus  the  slowly 
decomposing  material  will  be  sealed  within  the  tooth  substance, 
and  the  gas  that  is  formed  will  slowly  and  surely  drive  the  de- 
pressing bacterial  toxins  through  all  parts  of  the  tooth  and  even 
out  into  the  body  at  large.  Thus  the  peridental  membrane 
when  attacked  by  actual  infection  from  within  is  so  weakened  in 
its  bacterial  resistance  that  it  readily  accepts  any  infection  that 
may  be  either  floating  in  the  blood-stream  or  attempting  to  gain 
an  entrance  at  the  gum  margin. 

The  two  bleaching  agents  most  valuable  in  the  treatment 
of  discolored  teeth  are  a  30  per  cent,  aqueous  solution  of  peroxid 
of  hydrogen  and  a  saturated  aqueous  solution  of  oxaHc  acid. 
If  the  iron  of  the  hemoglobin  has  darkened  the  tooth,  as  is  indi- 
cated by  the  presence  of  the  brown  stain,  it  is  wise  to  use  the 
oxalic  acid  alternately  with  the  peroxid,  but  if  the  tooth  has  a 
gray  or  black  discoloration  and  has  not  been  stained  with  amal- 
gam or  previously  treated,  peroxid  alone  will  usually  be  able  to 
permanently  restore  the  tooth  to  its  normal  color. 

The  method  of  using  these  two  bleaching  agents  is  as  follows : 
The  root  canal  or  canals  should  be  sterilized  with  tricresol  and 
formahn  freshly  mixed.  Then  one  or  two  drops  of  50  per  cent, 
aqueous  solution  of  sulphuric  acid  should  be  placed  within  the 
pulp  cavity,  where  it  should  be  allowed  to  remain  for  a  few  min- 
utes. It  should  then  be  neutralized  with  a  concentrated  aqueous 
solution  of  bicarbonate  of  soda.    This  will  cause  the  formation 


TREATMENT   OF   ROOT   CANALS  I35 

of  carbon  dioxid  at  the  further  ramification  of  the  dentin  tubes, 
which  will  tend  to  sweep  out  any  loose,  decomposed  material 
that  may  be  present.     The  sulphuric  acid  is  also  a  powerful 
germicide,  and  such  an  application  seems  to  have  no  harmful 
effect  if  it  is  not  repeated  too  often,  and  if  it  is  not  allowed  to 
remain  upon  the  outside  surface  of  the  enamel  of  the  tooth. 
When  the  tooth  has  been  sterilized  and  the  loose  discoloration 
has  been  removed  from  the  pulp  chamber  and  its  environs  by 
the  mechanical  means  of  the  gas  formation,  and  the  tips  of  the 
canals  have  been  thoroughly  sealed  with  a  pellet  of  gutta-percha, 
the  actual  bleaching  may  be  attempted.    But  it  must  be  remem- 
bered that  it  is  just  as  necessary  for  the  root  under  the  gum  to 
be  bleached  as  it  is  for  the  tooth  crown,  if  permanent  results 
are  to  be  secured;  for  any  discoloration  that  is  left  anywhere 
within  the  tooth,  especially  within  the  pulp  canal,  will  tend  to 
become   infiltrated    throughout    the    entire    organ.      Therefore 
the  tip  of  the  root  should  be  sealed,  and  as  much  of  the  canal  as 
possible  should  be  left  open  to  the  action  of  the  bleaching  agents. 
The  best  way  to  do  this  is  to  fill  the  canal  completely  with  gutta- 
percha during  one  visit,  and  then  on  a  later  occasion,  when 
the  gutta-percha  is  absolutely  hard,  to  drill  it  out  almost  to  the 
apical  foramen,  leaving  the  tip  completely  sealed.    It  is  particu- 
larly necessary  for  the  tip  to  be  sealed  completely  when  bleaching 
is  undertaken,  for  if  the  bleaching  material  is  forced  up  through 
the  tip  into  the  gum  an  acute  abscess  is  likely  to  be  the  result. 
Let  us  recapitulate :    The  root  canal  has  been  opened  mechan- 
ically, cleansed,  and  sterilized.    It  has  been  flooded  with  50  per 
cent,  sulphuric  acid,  washed  out  with  bicarbonate  of  soda,  and 
the  end  of  the  root  has  been  sealed.    When  this  has  been  done 
the  root  canal  should  be  carefully  dried  and  a  twist  of  cotton  wet 
with  a  saturated  aqueous  solution  of  oxalic  acid  should  be  in- 
serted, and  then  a  small  electric  cautery  (see  Fig.  25)  should  be 
heated  to  a  point  just  below  redness  and  plunged  into  the  pulp 
cavity,  vaporizing  the  oxalic  acid  solution.    The  cotton  dressing 
should  be  removed  when  it  is  dry  and  the  process  repeated 
several  times.     Finally,  the  oxaHc  acid  and  cotton  should  be 
temporarily  sealed  tightly  within  the  pulp  chamber  with  cement 


136  MODERN   DENTISTRY 

and  the  patient  dismissed.  The  amount  of  acid  used  is  so  small 
that  there  is  no  danger  even  if  the  solution  escapes  into  the 
mouth  through  a  defective  seal  of  the  cavity.  When  the  patient 
returns  on  the  following  day  the  same  procedure  should  be 
carried  out  with  the  30  per  cent,  peroxid  of  hydrogen  solution. 
The  peroxid  is  particularly  effective  as  a  bleacher  when  it  is 
converted  into  steam  within  the  pulp  cavity,  since  the  oxygen 
thus  liberated  is  free  atomic  oxygen,  which  attacks  the  organic 
discoloration  not  merely  as  molecular  oxygen  would,  but  it 
attacks  it  with  all  the  force  that  is  usually  expended  by  the 
atoms  in  uniting  within  the  molecule.  When  the  tooth  has 
been  steamed  from  within  several  times,  cotton  wet  with  peroxid 
should  be  sealed  in  the  canal  with  cement,  and  then  the  outside 
of  the  tooth  gone  over  with  the  hot  instrument.  This  heat 
liberates  the  nascent  oxygen  under  pressure  and  causes  a  sudden 
whitening  of  the  tooth  substance  that  is  most  satisfactory  and 
effective.  If,  under  these  conditions,  the  apical  foramen  of  the 
canal  has  not  been  carefully  sealed,  the  oxygen  escaping  from 
the  solution  may  cause  an  abscess  by  rupturing  the  tissues 
on  the  outside  of  the  tooth.  With  oxalic  acid  the  danger  does 
not  exist  to  such  an  extent.  When  this  sealing  and  external 
ironing  has  been  done  several  times,  the  solution  can  be  sealed 
within  the  tooth  for  a  week  or  more  with  the  expectation  that 
the  heat  of  the  body  will  slowly  liberate  the  oxygen,  causing  a 
still  further  antiseptic  and  bleaching  effect.  At  the  end  of  each 
operation,  prior  to  the  final  filling,  the  pulp  canal  should  be 
flooded  with  hot  water  to  wash  out  the  soluble  iron  salts. 

Sometimes  when  the  peridental  membrane  is  particularly 
sensitive  the  pressure  of  the  gas  through  the  tooth  substance 
may  cause  an  external  irritation.  This  has  happened  very 
occasionally  in  my  experience,  and  when  it  does  occur  it  is  wise 
to  put  a  slight  vent  in  the  cement  seal  so  as  to  temporarily 
relieve  the  pressure. 

When  stains  occur  on  the  outside  of  the  enamel  of  a  tooth 
with  a  living  pulp  the  external  steaming  process,  just  described, 
can  be  effectively  used  on  the  enamel  if  the  tooth  is  not  over- 
sensitive to  heat. 


TREATMENT  OF  ROOT  CANALS  I37 

The  details  by  which  the  mouth  and  Hps  are  protected  from 
injury  or  irritation  by  napkin  or  rubber-dam  have  not  been  dwelt 
upon,  as  this  is  a  commonly  understood  dental  procedure. 

Root  Amputation  and  x-Ray  Diagnosis. — Let  us  now  take  up 
the  question  of  root  amputation,  preserving  a  part  of  a  tooth 
by  excision  either  of  the  tip  of  the  root,  or  in  the  case  of  molars, 
by  removing  the  necrosed  roots,  leaving  the  healthy  root  or 
roots  as  a  useful  support  for  filhng  or  crown. 

Amputation  of  roots  should  be  preceded  by  a  careful  x-ray 
study  of  the  region  involved.  Emphasis  is  laid  on  the  word 
careful  as  applying  both  to  the  method  of  taking  the  x-ray  and 
to  its  interpretation  in  conjunction  with  the  cHnical  facts.  The 
darkened  area  at  the  tip  of  a  root,  as  shown  by  an  x-ray  plate, 
may  indicate  absorption  or  the  presence  of  chronic  inflammation 
of  the  bone,  or  a  thickened  peridental  membrane.  The  too  clear 
differentiation  of  a  root  tip  in  the  alveolus  is  just  as  significant 
of  lost  vitaHty,  but  as  bones  and  roots  vary  in  density,  it  is  not 
always  easy  to  differentiate  and  diagnose  a  case  of  this  character. 
Therefore,  when  it  comes  to  saying,  by  x-ray  alone,  whether  a 
pyorrhea  pocket  is  getting  well  and  has  ceased  spreading  in- 
fection, or  is  increasing  so  as  to  be  a  menace  to  the  health  of 
the  patient,  the  x-ray  man  is  helpless,  and  frequently  makes 
himself  ridiculous  if  he  does  not  allow  caution  to  temper  his 
enthusiasm. 

The  following  is  a  case  in  point:  A  young  married  woman 
had  been  under  treatment  for  gum  infection  and  loose  teeth 
during  a  period  of  six  years,  and  had  showed  marked  improve- 
ment. The  gums  had  healed,  the  pus  had  ceased  to  flow,  and 
the  teeth  had  tightened.  There  was  unquestionably  progressive 
improvement.  Many  of  the  teeth  that  originally  were  so  loose 
that  they  could  have  been  pulled  out  by  the  fingers  had  become 
firm,  the  gums  around  them  had  assumed  a  healthy  color,  and 
the  pockets  of  infection  had  disappeared.  There  were  two  or 
three  teeth  that  did  not  show  the  improvement  of  the  rest,  but 
the  mouth  as  a  whole  was  becoming  comfortable  and  healthy. 
In  the  meanwhile  the  patient  suffered  from  enteroptosis  and  went 
to  her  physician,  who  sent  her  to  a  prominent  x-ray  man  for  an 


138  MODERN  DENTISTRY 

examination  of  her  bowel  convolutions.  Incidentally,  he  took  an 
x-Ta,y  of  her  teeth  and  reported  to  her  physician  that  he  did  not 
find  a  single  healthy  tooth  in  the  upper  jaw  and  only  three  in  the 
lower.  This  report  was  enthusiastically  received  by  her  physician, 
who  said  that  the  :r-ray  report  was  one  of  the  most  beautiful 
and  complete  he  had  ever  known,  and  complimented  the  x-ray 
specialist  very  highly  on  the  brilHancy  of  his  report.  As  a  matter 
of  fact,  all  of  the  teeth  except  three  were  in  a  fairly  healthy  con- 
dition and  certainly  were  not  causing  the  general  systemic 
infection.  Two  of  these  three  still  had  a  good  chance  of  heahng 
as  was  later  demonstrated.  This  was  a  case  where  it  was  im- 
possible to  interpret  the  x-ray  of  the  mouth  correctly  without 
knowing  the  clinical  facts  and  history  of  the  case. 

Perhaps,  then,  it  might  be  wise  to  say  that  we  should  learn 
all  that  we  can  by  the  x-ray  plate,  but  not  rely  too  much  on  the 
finality  of  its  data,  for  many  a  surgeon  knows  that  two  ends  of 
a  bone  will  make  a  thoroughly  practical  union  even  though  the 
x-ray  would  conclusively  demonstrate  that  the  dressing  should 
be  removed  and  the  patient  subjected  to  the  agony  of  an  attempt 
to  get  a  juxtaposition  that  would  be  only  theoretically  an  im- 
provement. The  author  does  not  wish  to  be  interpreted  as 
discrediting  the  x-ray;  he  discredits  the  overzealous  interpre- 
tations of  some  x-ray  men  who  claim  that  all  other  methods  of 
diagnosis  are  to  be  subservient  to  their  valuable  but,  in  reality, 
limited  scope  of  vision. 

The  method  of  procedure  in  the  amputation  of  the  necrotic 
tip  of  a  root  follows.  Figs.  56,  57  representing  any  typical  single- 
rooted  tooth: 

A  2-c.c.  hypodermic  syringe  is  filled  with  a  0.5  per  cent, 
solution  of  novocain  and  suprarenin.  lodin  should  be  appHed 
over  the  places  to  be  punctured.  The  lip  is  retracted  and  the 
tip  of  the  needle  is  inserted  beneath  the  periosteum  near  the  tip 
of  the  root  on  the  labial  side.  The  2  c.c.  are  then  injected  and 
the  same  procedure  is  carried  out  in  the  lingual  surface.  A  i  per 
cent,  solution  may  be  used  and  half  the  amount  injected  on  each 
side  if  desired.  If  this  is  done  properly,  at  the  end  of  five  min- 
utes the  surrounding  parts  should  be  white  and  insensitive. 


TREATMENT  OF  ROOT  CAXALS 


139 


Then  an  opening  is  made  through  the  gum  with  a  sharp  knife, 
and  the  periosteum  loosened  and  pushed  up  with  a  chisel.  The 
wound  is  kept  open  by  a  retractor  thoroughly  exposing  the  al- 
veolar process.  In  a  certaia  number  of  cases  the  tip  of  the 
root  and  necrotic  cavity  will  be  exposed  to  view,  when  the  tip 
may  be  amputated  and  the  dead  bone  removed  with  bone 
drills  and  spoon-shaped  excavators.  It  is  especially  necessary 
that  all  of  the  dead  bone  and  abscess  sac  should  be  removed. 
The  suprarenin  makes  this  a  practically  bloodless  operation. 


Fig.  56. — A,  Cross-section  of 
tootli;  B,  the  lip;  C,  abscess  in  the 
bone  at  the  tip  of  the  root. 


Fig.  57. — Operation  of  root  ampu- 
tation completed:  A,  Tooth;  B,  lip; 
C,  excised  abscess  area;  D,  gutta- 
percha root  canal  filling;  E,  unfilled 
portion  of  root  canal. 


If  the  root  canal  has  previously  been  sterilized  and  filled  to 
the  tip  with  gutta-percha,  the  blood-clot  can  now  be  allowed  to 
form  and  the  incision  in  the  periosteum  and  gum  can  be  stitched 
together,  thus  completeing  the  operation.  But  if  the  canal  has 
only  been  sterilized,  the  point  of  a  gutta-percha  cone  should  be 
pushed  through  the  end  of  the  root  and  trimmed  smoothly  with  a 
hot  instrument.  But  in  many  instances  the  pushing  back  of  the 
periosteum  and  gum  does  not  expose  the  root  and  abscess,  and 
in  these  cases  great  nicety  in  laying  bare  the  root  is  required. 
For  instance,  in  Fig.  58,  let  the  lateral  incisor  ^  be  a  tooth  with 
achronic  abscess  at  the  end  of  the  root,  as  shown  by  dotted 


I40 


MODERN    DENTISTRY 


Fig.  58. — Procedure  where  the  alveolar  plate  above  the  abscess  shown  by  the 
dotted  circle  is  unbroken.  The  cross  lines  indicate  the  alveolar  plate.  Gum  and 
periosteum  are  not  shown. 


Fig.  59. — The  two  cuts  shown  near  the  tip  of  the  root  of  tooth  A  demonstrate  the 
first  steps  in  the  removal  of  the  bony  plate  over  the  abscessed  root  tip. 


TREATMENT    OF    ROOT    CANALS 


141 


Fig.  60. — The  connecting  line  made  by  a  chisel,  at  the  base  of  the  two  up- 
right cuts,  shows  how  the  alveolar  plate  should  be  divdded  previous  to  its  being 
lifted  up  with  the  chisel. 


Fig.  61. — Necrotic  tip  of  the  abscessed  tooth  exposed  after  the  covering  plate  has 

been  removed. 


142  MODERN  DENTISTRY 

lines  under  the  cross  lines  that  indicate  the  overlying  alveolar 
plate.    The  gum  and  periosteum  being  retracted,  are  not  shown. 

Figure  59  shows  two  cuts  through  the  bony  plate  made  on  each 
side  of  the  affected  root.  Then  a  sharp  chisel  with  hand  pressure 
alone  is  pressed  on  the  bone  over  the  root  so  as  to  connect  the 
ends  of  the  two  cuts,  as  shown  by  the  additional  Hne  in  Fig.  60, 
and  the  entire  bony  plate  is  lifted  up  with  the  chisel  exposing 
the  root  tip  in  the  abscess  opening  of  the  bone  as  in  Fig.  61. 
When  the  root  is  exposed,  if  the  abscess  is  still  higher  there  is 
no  difficulty  in  working  up  toward  it,  cutting  off  the  tip,  and  cu- 
reting  and  imishing  as  just  described.  When  complete  cureting 
does  not  seem  possible,  as  is  sometimes  the  case,  the  wound  should 
be  packed  with  iodoform  gauze  and  kept  open  by  repeated 
dressings  until  healthy  granulations  completely  cover  the  bottom 
of  the  wound  and  show  conclusively  that  healing  is  progressing 
satisfactorily.  To  always  treat  such  a  wound  aseptically  seems 
absurd,  for  to  make  such  a  wound  surely  aseptic  would  mean 
such  an  extension  of  the  surgical  area  that  much  valuable  tis- 
sue would  be  lost  and  many  teeth  sacrificed.  Therefore,  since 
at  times  it  is  hardly  possible  to  closely  differentiate  between 
dead  bone  and  living  bone  with  a  bur,  in  doubtful  cases  it  seems 
best  to  keep  the  wound  open  until  it  is  apparent  that  all  the  bone 
is  healing  properly,  so  that  all  parts  that  do  not  heal  can  be 
cureted  until  they  do  heal.  The  mouth  of  the  wound  should 
be  kept  open  until  granulations  cause  the  cavity  to  be  shallower 
than  it  is  wide.  Then  heaUng  will  ordinarily  progress  to  a 
satisfactory  termination.  This  procedure  of  root  amputation 
applies  to  all  of  the  single-rooted  teeth  and  the  upper  first  bicus- 
pid, but  when  we  come  to  the  molar  teeth  a  different  procedure 
is  usually  necessary. 

Root  Excision. — ^When  the  buccal  root  or  roots  of  the  first 
or  second  upper  molars  have  become  necrotic  at  the  tip,  the  same 
procedure  can  be  used  as  has  just  been  recommended  for  the 
single-rooted  teeth,  but  when  the  palatal  root  of  the  upper  first 
or  second  molars  has  become  necrotic  at  the  tip,  complete  ex- 
cision of  the  root  from  the  rest  of  the  tooth  is  usually  to  be  pre- 
ferred.    It  has  been  the  author's  clinical  experience  that  necrosis 


TREATMENT  OF  ROOT  CANALS 


143 


or  absorption  at  the  tip  of  the  palatal  root  is  usually  associated 
with  a  pyorrhea  pocket  at  the  bifurcation  of  the  roots. 

For  instance,  let  us  suppose  Fig.  63  represents  a  superior 
first  molar.  A  represents  a  pocket  of  infection  in  the  bifurcation 
of  the  roots  beneath  the  gum  which  extends  its  influence  to  B, 
which  represents  a  necrotic  tip  of  the  palatal  root;  F  represents 
the  crown  of  the  tooth;  C  represents  the  palatal  root;  D  and  E, 
the  buccal  roots.  Such  a  condition  usually  exists  when  the  pulp 
has  either  completely  died,  or  when  it  has  become  so  infected 
that  the  living  pulp  is  causing  an  abscess  at  one  of  the  root  tips, 


If 


Fig.  62. — Bone  drills. 


usually  the  palatal.  Volumes  have  been  wTitten  about  the  in- 
struments that  can  curet  and  cure  such  a  spot  as  A  represents, 
surrounded  as  it  is  by  three  roots,  but  any  conscientious  ex- 
perienced dentist  knows  that  this  is  a  more  theoretic  than  a 
practical  possibility.  Curetting  and  stimulating  antiseptics 
may  quiet  "and  mask  such  an  abscess,  but  in  ninety  times  out 
of  a  hundred  no  treatment  will  cure  it  so  that  there  will  be 
reattachment  of  the  membranes  to  the  root;  and  as  such  an 
abscess  may  result  in  grave  systemic  complications,  any  such 
temporizing  procedure  should  be  out  of  the  question.    The  first 


144 


MODERN   DENTISTRY 


step,  under  such  conditions,  is  to  anesthetize  and  remove  the  pulp, 
as  has  just  been  described.  When  this  has  been  done,  a  fissure 
bur  should  be  inserted  between  the  buccal  and  palatal  roots  at 
the  point  A,  and  a  cut  should  be  made  through  into  the  pulp 
chamber  and  up  to  the  grinding  surface,  as  is  designated  by  the 
dotted  line.  This  may  either  be  repeated  on  the  other  side,  or 
the  cut  may  be  continued  directly  through  the  pulp  chamber 
until  the  crown  has  been  completely  cut  in  two,  leaving  one  half 
attached  to  the  buccal  roots  and  the  other  half  to  the  palatal 
root.  Then  the  novocain  mixture  should  be  injected  freely 
about  the  palatal  root  until  the  gum  is  white  and  insensitive, 
when  a  single  pry  with  a  spoon  elevator  between  the  adjacent 
molar  and  the  palatal  root  will  extract  it,  leaving  the  buccal 


Fig.  63.  Fig.  64.  Fig.  65.  Fig.  66.     Fig.  67.       Fig.  68. 

Figs.  63-68 — Progressive  steps  by  which  a  necrotic  palatal  root  may  be  ex- 
cised from  the  sound  portion  of  the  tooth,  and  the  steps  by  which  the  remaining 
healthy  portion  of  the  tooth  may  be  restored  to  comfort  and  usefulness. 


roots  with  the  attached  half  of  the  crown  as  in  Fig.  64.  G  rep- 
resents exposed  pulp  chamber  not  yet  prepared  for  filHng.  Of 
course  forceps  can  be  used  to  extract  the  root  if  desired,  but  the 
elevator  usually  gives  the  best  results.  The  pulp  chamber  and 
canals  in  the  buccal  roots  should  now  be  sterilized  with  formalin 
and  tricresol  and  cut  out  and  filled.  If  the  attached  portion  of 
the  crown  is  sound  and  undecayed  it  can  be  dovetailed  as  in 
Figs.  65  and  66  and  filled  with  any  filling  material  or  with  an 
inlay  (Fig.  67),  so  that  when  it  is  completed  it  will  resemble 
Fig.  68.  It  will  then  resemble  a  large,  plump,  useful  bicuspid 
with  two  roots,  turned  on  its  side.  Such  a  tooth  will  give  excel- 
lent service  in  the  mastication  of  food,  and  as  regards  looks, 
from  the  outside  it  appears  just  as  before,  since  the  buccal  cusps 
have  not  been  altered.    Where  the  crown  is  decayed  or  missing 


TREATMENT  OF  ROOT  CANALS 


145 


the  remaining  roots  should  be  restored  with  amalgam,  as  de- 
scribed in  Chapter  VII,  and  fitted  with  a  suitable  crown,  either 
of  gold  or  platinum,  with  a  porcelain  facing. 

When  a  buccal  root  of  a  superior  first  or  second  molar  is 
necrotic  and  has  to  be  removed,  somewhat  the  same  procedure 
should  be  followed.  In  Fig.  69,  A  represents  a  necrotic  buccal 
root,  B  the  palatal,  and  C  the  normal  buccal  root,  D  the  crown 
of  the  defective  tooth,  and  E  the  crown  of  the  adjacent  tooth 
to  which  a  sufficient  contour  should  be  made  or  preserved. 
The  dotted  fine  shows  how  the  cut  should  be  made  so  as  to 
maintain  the  supporting  contour  against  the  adjacent  tooth  E. 
This  can  be  made  with  a  fissure  bur  in  a  manner  similar  to  the 


Fig.  69.  Fig.  70. 

Figs.  69,  70  show  the  method  of  removing  a  defective  buccal  root  from  an  upper 

molar  so  as  to  preserve  the  approximal  contact  with  the  adjacent  teeth. 


method  just  described,  and  should  be  done  after  the  pulp  chamber 
and  the  root  canals  in  the  two  sound  roots  have  been  fiUed. 
When  the  root  has  been  cut  absolutely  free  from  the  tooth, 
novocain  can  be  used  and  the  root  can  be  extracted  with  an 
elevator.  If  the  crown  is  not  perfect,  and  a  good  support  against 
the  adjacent  tooth  is  not  present,  the  crown  should  be  made 
perfect  with  some  suitable  filHng.  Of  course,  the  natural  crown, 
if  preserved,  should  be  poUshed  smooth  with  stones  where  the 
root  has  been  excised. 

Figure  70  represents  the  crown  D  with  the  defective  buccal 
root  removed.  When  this  operation  is  properly  completed  it 
should  be  possible  to  easily  cleanse  the  contours  of  the  inter- 
dental space  with  floss-silk. 


146 


MODERN   DENTISTRY 


When  we  come  to  the  lower  first  and  second  molars  the 
procedure  is  the  same  but  more  simple,  as  here  we  have  usually 
but  two  roots.  As  described  in  the  previous  case,  when  a  ne- 
crotic root  is  associated  with  a  partly  living  pulp,  the  pulp  in  all 
the  canals  of  the  infected  tc^oth  should  be  removed  prior  to  the 
excision  of  the  root.  When  this  has  been  accomplished  we  can 
proceed  to  the  excision  and  removal  of  the  necrotic  root  in  ques- 
tion. Figure  71  represents  a  first  lower  molar  with  an  unde- 
cayed  crown.  The  anterior  root  A  is  necrosed  and  the  pulp  dead. 
The  posterior  root  is  sound,  with  a  living  pulp.  B  is  the  crown, 
C  the  pulp  outline,  D  the  spot  of  infection  in  the  bifurcation 
of  the  roots. 


Fig.  71.  Fig.  72. 

Figs.  71,  72  show  how  the  defective  anterior  root  of  a  two-rooted  lower  molar  can 
be  removed  and  the  contact  with  the  adjacent  tooth  preserved. 


The  abscess  at  the  fork  of  the  roots  makes  a  complete  canal 
of  infection  underneath  the  tooth.  Let  us  suppose  that  the  pulp 
canal  has  been  opened  and  the  living  pulp  removed.  If  the  crown 
is  undecayed,  a  complete  operation  can  be  performed  by  insert- 
ing the  fissure  bur  at  the  bifurcation  of  the  roots,  and  excising 
the  root  along  the  dotted  line  E,  so  that  the  contour  and  approxi- 
mation against  the  adjacent  tooth  can  be  retained.  When  this 
has  been  done,  the  root  can  be  pried  out  sidewise  by  means  of  an 
elevator,  leaving  the  tooth  as  in  Fig.  72.  The  remaining  pulp 
canal  in  the  posterior  root  can  then  be  sterilized  in  the  usual 
way  and  the  root  and  crown  filled,  care  being  taken  to  smooth 
the  filling  within  the  pulp  chamber  where  the  root  was  excised. 
Where  the  crown  of  the  molar  is  badly  decayed,  the  remaining 
root  should  be  fitted  with  a  properly  contoured  crown,  so  that  it 


TREATMENT  OP  ROOT  CANALS 


147 


will  rest  securely  against  the  adjacent  tooth.  This  support  is  most 
essential  and  will  prevent  undue  tipping  until  the  bony  socket 
of  the  extracted  root  has  completely  filled  in  and  healed  (Fig.  73). 
If  the  root  is  decayed  below  the  gum  it  must  be  fiUed  up  with 
amalgam  and  properly  contoured  before  it  is  covered  by  a  suitable 
crown,  as  described  in  Chapter  VII.  If,  as  sometimes  happens, 
the  adjacent  tooth  is  decayed  or  already  has  a  filling,  the  extra 
contour  necessitated  by  the  loss  of  the  root  can  be  divided  be- 
tween the  two  teeth,  the  filling  being  made  larger,  and  the  crown 
being  correspondingly  decreased  in  size,  as  in  Fig.  74.  Some- 
times we  have  a  lower  molar  where  the  tips  of  the  roots  are 
healthy,  but  the  gum  and  alveolar  process  have  receded  to  such 


Fig.  73- — Diagrammatic  method  of 
restoring  a  single  molar  root  with  a 
crown  so  that  the  interdental  space  can 
be  preserved. 


Fig.  74. — Same  case,  with  the  inter- 
dental space  divided  between  the  crown 
and  the  filling  in  the  adjacent  tooth. 


an  extent  that  the  infection  has  worked  completely  through  the 
bifurcation  of  the  roots,  forming  a  channel  under  the  tooth 
that  the  ordinary  daily  cleansing  cannot  possibly  reach  or 
restore  to  healthy  condition,  as  in  Fig.  75. 

A  represents  the  crown  of  a  lower  molar,  C  represents  the 
gum  line,  showing  the  recession,  and  B  represents  the  spot  of 
infection  and  tartar  in  the  bifurcation  of  the  roots.  The  hope- 
less future  of  such  a  molar  is  apparent.  The  gum  that  has  re- 
ceded cannot  be  restored  to  cover  up  the  bifurcation,  and  the 
opening  will  be  a  constant  invitation  for  the  lodgment  of  bacteria 
and  tartar,  which  will  not  only  result  in  the  eventual  loss  of  the 
tooth,  but  also  in  grave  systemic  infection.  Such  a  condition 
cannot  possibly  be  tolerated  even  if  the  remedy  demands  the 


148 


MODERN  DENTISTRY 


loss  of  the  tooth.  But  such  a  sacrifice  is  by  no  means  always 
necessary.  The  principal  need  is  a  chance  to  thoroughly  cleanse 
the  channel  under  the  tooth  and  a  chance  to  keep  it  clean,  and 
that  can  be  accomplished  as  in  Fig.  76.    When  the  pulp  has  been 


1/  1/ 

Fig.  75. — Molar  with  the  bifurca- 
tion of  the  roots  exposed  and  infected, 
where  cleansing  is  impossible. 


Fig.  76. — Tooth  divided  and  con- 
verted into  two  bicuspids  which  can 
readily  be  cleansed  with  brush  and 
dental  floss. 


devitalized  and  the  root  canals  filled,  the  bifurcation  should  be 
boldly  extended  up  through  the  middle  of  the  crown  of  the  molar 


Fig.  77. — ^Two  parts  of  tooth  strapped  together  by  a  cemented  staple  for  the 
purpose  of  securing  greater  stability.  Here  the  interdental  space  must  be 
cleansed  with  dental  floss  inserted  beneath  the  staple  by  a  wire  needle. 


until  the  roots  are  completely  separated;  and  the  separated 
parts  of  the  crown  should  be  filled  as  though  each  was  a  bicuspid, 
leaving  a  cleansing  space  through  which  the  floss-silk  can  be 
passed  just  as  in  any  of  the  approximal  spaces  of  the  other  teeth. 


TREATMENT  OF  ROOT  CANALS  I49 

If  there  is  excessive  mobility  a  staple  of  platinum  can  be  inserted 
in  the  adjacent  iillings  so  as  to  make  them  join  (Fig.  77).  If 
this  is  done,  the  floss-silk  will  have  to  be  passed  underneath 
the  staple  by  means  of  a  needle  with  a  blunt  point.  The  floss-silk 
can  be  sHpped  through  the  eye,  the  flexible  needle  passed  between 
the  teeth  that  are  stapled  together  and  drawn  through,  carrying 
the  silk  with  it.  The  silk  can  then  be  swept  over  all  the  surfaces 
and  the  bacterial  deposits  entirely  removed. 

Sometimes  when  the  roots  have  been  cut  apart  and  the  pulp 
chamber  is  still  open,  it  is  well  to  put  in  a  gutta-percha  filling 
for  a  month  or  so,  in  order  that  the  mastication  on  the  gutta- 
percha shall  spread  the  two  portions  of  the  divided  tooth  into 
absolute  contact  with  the  adjacent  teeth;  thus  the  fillings  put 
in  the  two  halves  of  the  pulp  chamber  will  have  a  more  perfect 
support  from  the  dental  arch.  When  the  crown  is  badly  decayed 
the  separate  roots  must  be  capped,  as  is  ordinarily  done  with 
single-rooted  teeth. 


CHAPTER  VII 

FILLINGS 

Hammered  Gold.  Inlays — Porcelain  and  Gold.  Advantages 
and  Disadvantages  of  Cement.  Silicious  Cement,  Amalgam, 
and  Gutta-Percha 

Operative  Efficiency. — Frederick  W.  Taylor  in  his  scientific 
shop  management  showed  conclusively  that  there  should  be  no 
such  thing  as  unskilled  labor.  He  started  on  the  basis  that  there 
is  a  best  way  to  do  everything.  He  searched  until  this  best 
way  was  discovered,  and  then  he  saw  to  it  that  each  workman 
under  his  care  was  instructed  and  even  compelled  to  use  this 
way.  Thus  the  workmen,  instead  of  using  various  methods 
according  to  their  individual  whims,  all  became  skilled  workmen, 
to  the  great  benefit  of  their  employers  and  themselves.  By  his 
plan  as  simple  a  proceeding  as  loading  pig-iron  on  a  car  was 
reduced  from  a  haphazard  process  to  a  science.  The  man  that 
could  load  only  12.5  tons  of  pig-iron  a  day  when  left  to  his 
own  devices,  under  scientific  management  readily  loaded  47 
tons  in  the  same  time.  Mr.  Taylor  found  that  21  pounds  was 
the  proper  weight  for  each  shovelful  for  the  average  man  if  he 
would  do  his  best  work  and  not  become  tired  during  the  day;  he 
also  showed  the  men  the  most  efficient  method  of  shoveling.  Then, 
by  having  shovels  of  various  sizes  to  suit  the  kind  of  material 
shoveled,  he  made  a  man  carry  in  his  shovel  2 1  pounds,  whether 
he  was  shoveling  iron  ore,  coal,  or  sawdust. 

The  great  value  of  such  a  plan  is  obvious.  Dentists  are  suffer- 
ing from  the  lack  of  just  such  training.  Each  teacher  in  the  dental 
schools  is  apt  to  advocate  the  methods  used  by  his  former 
teachers,  which  methods  are  varied  according  to  the  instructor's 
personal  skiU  or  mechanical  bias.  There  is  no  standard  best 
method   which   all   students   are   taught.      Some   men   employ 

ISO 


FILLINGS  151 

methods  that  will  obviously  give  better  results  in  one-half  the 
time.  These  methods  should  not  be  brushed  aside  as  requiring 
skill  unattainable  by  others.  They  should  be  studied  and  col- 
lected into  a  system  that  would  stand  as  a  model  for  all  teachers 
to  use  until  scientific  research  has  demonstrated  a  further  advance. 
In  fact,  the  dentists  of  the  future  should  be  taught  dentistry 
in  reference  to  a  recognized  standard,  both  as  regards  rapidity 
and  efficiency.  Since  we  are  working  on  living  organisms,  it 
is  especially  necessary  that  no  judicious  means  of  shortening 
the  time  of  an  operation  should  be  overlooked. 

In  a  surgical  operation  rapidity  of  action  is  a  recognized 
element  of  great  importance.  The  longer  the  patient  is  kept 
under  ether,  the  greater  is  the  danger  from  exhaustion  and  sur- 
gical shock.  At  such  a  time  a  life  may  hang  on  the  question 
of  ten  minutes.  Before  the  days  of  anesthetics  speed  was  con- 
sidered of  even  more  importance  than  now.  And  yet  some  den- 
tists perform  operations  on  conscious  patients  sometimes  con- 
suming two  or  three  hours  of  agonizing  procedure  to  accomplish 
a  result  that  other  dentists  will  attain  in  one-half  the  time  by 
work  that  is  comparatively  painless.  Dentists  will  always 
differ  in  their  relative  skill  and  speed,  but  such  differences  as 
now  exist  can  only  come  from  defective  technic.  Some  dentists 
prepare  cavities  for  filling  in  five  minutes  that  other  operators 
require  an  hour  to  shape.  A  man  will  sometimes  take  ten  or 
fifteen  minutes  to  adjust  a  rubber-dam  under  a  sensitive  gum, 
causing  great  laceration  of  the  peridental  membranes,  in  order 
to  put  in  a  gutta-percha  or  amalgam  filling  that  ought  not  to 
have  taken  over  two  or  three  minutes  to  insert  with  the  aid  of 
the  cotton  roll  or  napkin. 

The  Old  Hammered  Filling. — For  instance,  what  could  be 
more  ridiculous  than  the  present  employment  of  the  hammered 
gold  filling  for  repairing  a  decayed  spot  in  a  tooth?  It  is  a  long, 
tedious,  painful  process  to  both  the  patient  and  the  dentist. 
The  most  skilful  operator  has  a  decided  percentage  of  non- 
bacteria-proof  edges,  and  the  average  dentist  seldom  makes  any 
bacteria-proof  edges  at  all,  so  that  the  tooth  filled  with  ham- 
mered gold  ordinarily  begins  to  decay  as  soon  as  the  filling  is 


152  MODERN   DENTISTRY 

inserted.  Especially  is  this  so  if  the  filling  is  between  the  teeth, 
where  the  mastication  of  food  will  not  sweep  it  clean  and  the 
bacterial  plaques  are  allowed  to  grow  upon  it  unmolested. 
Apropos  of  the  way  a  joint  that  is  not  bacteria-tight  can  be  a 
source  of  decay,  I  might  mention  an  experience  of  my  own 
early  days  of  practice.  It  was  during  my  first  year  after  grad- 
uation that  a  child  came  to  me  with  characteristic  softening 
of  the  sulci  in  the  four  upper  bicuspids.  The  teeth  were  sensi- 
tive to  the  blows  of  the  hammer,  and  yet  I  cut  out  the  four  sulci 
and  inserted  four  shallow  gold  fillings.  Accurate  condensation  of 
the  gold  was  impossible  owing  to  the  fact  that  the  tips  of  the 
roots  had  not  been  formed  sufficiently  to  withstand  the  stroke 
of  a  strong  enough  blow  to  do  the  work.  In  two  years  the  child 
returned,  and  where  two  of  the  fillings  had  dropped  out  there 
was  no  decay,  and  where  the  two  remaining  ones  were  still 
cHnging  to  their  undercuts,  well-defined  decay  was  making 
its  insidious  inroads  toward  the  pulp.  The  two  fillings  that  had 
dropped  out  had  fortunately  done  so  before  the  decay  had  had  a 
chance  to  become  intrenched  in  the  imperfect  margins,  leaving 
cavities  that  were  shallow  enough  to  be  self-cleansing  by  the 
action  of  mastication.  Ever  since  that  experience  I  have  merely 
polished  out  these  soft  sulci  wherever  it  was  possible  to  leave 
them  with  hard,  perfect  cups  of  enamel  that  were  self -cleansing. 
This  is  always  possible  if  the  tooth  is  examined  for  such  soft 
spots  as  soon  as  it  comes  through  the  gum.  It  cannot  be  stated 
too  often  that  the  thinnest  coating  of  enamel  is  a  far  better 
protection  than  the  best  filling  that  has  yet  been  invented. 

We  constantly  hear  of  the  beautiful  gold  fillings  with  perfect 
edges  that  lasted  over  fifty  years.  In  speaking  of  such  a  filling 
it  is  invariably  intimated  that  with  careful  technic  perfect  fillings 
are  always  possible.  In  my  experience,  however,  even  the  den- 
tists most  skilful  in  making  hammered  gold  filKngs  have  had  a 
high  percentage  of  failures,  and  most  of  them  frankly  admit  it. 

I  continued  to  put  in  hammered  gold  fillings  for  some  fifteen 
years,  and  finally  even  made  gold  fiUings  that  had  a  specific 
gravity  greater  than  cast  gold.  I  have  put  in  gold  fillings  that 
have  now  lasted  twenty-five  years,  and  admit  that  probably 


FILLINGS  153 

this  is  due  more  to  the  fact  that  the  gums  have  receded,  leaving 
the  margins  self-cleansing,  than  to  any  intrinsic  value  in  the 
method.  But  such  a  fact  does  not  prove  in  the  least  degree  that 
the  hammered  gold  filling  or  the  gold  filling  put  in  against  bare 
dentin  is  not  now  antiquated.  When  it  is  necessary  to  use  gold 
to  resist  the  force  of  mastication  it  should  always  be  put  in  with 
cement  as  a  bond  between  it  and  the  tooth  structure.  By  this 
means  a  bacteria-tight  joint  can  be  insured,  and  every  filling 
that  is  inserted  will  faithfully  perform  its  part  of  the  tooth 
preservation,  whether  it  is  inserted  by  expert  or  beginner.  This 
is  especially  so  since  the  advent  of  the  new  silicious  cements 
that  are  insoluble  in  the  mouth,  and  have  a  strength  of  substance 
that  makes  them  suitable  for  attaching  fillings  to  the  tooth 
structure.  The  cement  also  protects  the  tooth  from  the  shock 
due  to  the  great  thermal  conductibility  of  the  gold. 

Even  when  the  only  cements  available  were  soluble  in  the 
mouth,  the  inlay  fairly  won  its  way  against  the  hammered  gold 
filling,  both  because  it  preserved  more  teeth  and  because  it 
avoided  the  long,  battering  strain.  But  now,  with  an  almost  in- 
soluble cement  available,  the  inlay  should  always  be  preferred 
wherever  a  hammered  gold  filling  might,  in  the  past,  have  been 
deemed  advisable.  In  view  of  the  fact  that  the  silicious  cements 
are  being  so  perfected  as  to  insolubility,  color,  translucency  and 
strength  of  material,  it  is  a  question  whether  in  time  they  may 
not  largely,  if  not  entirely,  supplant  all  of  the  other  fillings,  the 
inlay  itself  not  being  excepted.  In  fact,  this  almost  insoluble 
cement,  capable  of  absolutely  matching  a  tooth,  may  sweep  away 
the  necessity  for  a  large  part  of  the  intense,  mechanical  refine- 
ment that  has  so  loaded  down  the  dentist  in  the  past,  and  give 
him  the  time  essential  for  mastering  the  medical  aspects  of  his 
work.  With  the  hammering  of  gold  fillings  eliminated,  and  gold 
inlays  made  in  five  to  fifteen  minutes  rather  than  in  an  hour  or 
two,  with  crowns  and  bridges  set  in  a  cement  that  will  conceal  the 
joint  of  the  porcelain,  and  fillings  made  boldly  above  the  gum 
because  the  color  of  the  teeth  can  be  matched,  two-thirds  of 
the  mechanical  drudgery  of  the  dental  student  can  be  thrown 
into  the  scrap  basket  of  dead  processes,  and  he  will  be  able  to 


154  MODERN  DENTISTRY 

devote  the  time  thus  saved  to  the  study  of  pathology,  bacteri- 
ology, immunology,  and  surgery.  With  the  new  dentistry  thus 
instituted,  it  is  possible  that  false  teeth,  crowns,  bridges,  fillings, 
and  pyorrhea  instrumentation  will  be  reduced  in  volume  to  i  per 
cent,  of  their  present  appalling  proportions,  and  the  future 
medically  trained  dentists  will  be  able  to  cope  with  the  disease 
of  mouth  infection,  now  almost  universal,  through  efficient 
instruction  of  the  piiblic  in  the  technic  of  scientific  mouth  hygiene. 
Before  the  days  of  plastics,  the  making  of  a  filling  was  a  very 
serious  and  exhaustive  problem,  yet  many  dentists,  in  spite  of 
the  general  improvement  in  materials,  are  still  using  the  materials 
and  methods  of  the  dark  ages.    Simple  cavities  in  the  grinding 

surfaces  of  molars  and  bicuspids,  cavities 
in  the  sides  of  the  teeth  where  there  is 
no  force  of  mastication  to  be  resisted,  as 
well  as  the  compound  cavities,  are  still 
hammered  full  of  gold,  with  useless 
agony  and  fatigue  to  both  dentist  and 
patient.  But,  fortunately,  the  great 
majority  of  these  cavities  can  now  be 
quickly  and  permanently  filled  with 
Fig.  78.-Arrow  represents  siHcious  cement.  The  filKngs  that  Can 
point  of  cleavage.  be   safely  made  with    silicious    cement 

are  those  that  do  not  receive  the  force 
of  mastication,  and  those  that  do  receive  it,  but  are  supported 
on  all  sides  by  enamel  walls;  for  silicious  cement  is  insoluble, 
strongly  resists  abrasion  and  withstands  a  high  crushing  strain. 
When,  however,  a  filHng  is  not  supported  on  all  sides,  as  in  an 
approximal  contour  cavity,  such  as  we  find  in  molars  and  bi- 
cuspids, and  receives  the  full  force  of  strong  mastication,  the 
cement  is  apt  to  crack  off,  its  cleavage  resistance  being  particu- 
larly low.  In  such  cases  an  inlay  set  in  silicious  cement  should 
be  used  (Fig.  78). 

Porcelain  Inlays. — Such  an  inlay  may  be  of  either  porcelain 
or  gold.  Where  excessive  force  is  to  be  withstood  and  the  filling 
is  out  of  sight,  the  gold  should  be  used  with  modern  silicious 
cement  as  a  binder.     But  where  the  inlay  is  plainly  visible, 


FILLINGS  155 

porcelain  may  be  used,  as  it  can  be  matched  to  the  tooth  so  as  to 
be  really  invisible,  and  it  has  sufficient  strength  to  withstand 
the  force  of  mastication  to  an  astonishing  degree.  Delicate, 
frail  porcelain  tips  cemented  on  the  fractured  corners  of  incisors 
have  already  given  good  service  for  fifteen  years  and  show  every 
sign  of  lasting  indefinitely.  It  is  true  that  any  chance  blow  or 
bite  on  a  piece  of  bone  or  stone  may  dislodge  them  at  any  time, 
but  that  may  also  be  said  of  a  corner  of  a  natural  tooth.  The 
wonder  is  not  that  a  few  insecure  or  frail  inlays  break  away, 
the  great  v/onder  lies  in  the  fact  that  so  many  of  them  last 
indefinitely. 

In  displacing  hammered  gold  for  porcelain  we  are  confronted 
with  the  question:  WiU  porcelain  withstand  the  force  of  masti- 
cation, not  better  than  gold,  but  sufficiently  well  to  be  worth 
while?  There  is  no  question  of  comparing  it  with  gold,  for  in 
porcelain  we  have  brittleness  as  an  ob\dous  danger,  and  therefore 
in  using  porcelain  as  an  inlay  we  must  carefully  consider  its 
relative  strength  and  brittleness. 

Porcelain  Strength. — The  principal  forces  that  tend  to  dis- 
lodge a  porcelain  tip  are  pressure,  shear,  and  percussion.  The 
more  the  force  is  exerted  longitudinally,  that  is,  along  the  axis 
of  the  tooth,  and  the  nearer  it  is  exerted  to  the  cement  base,  the 
less  tendency  there  is  for  fracture.  The  more  the  force  is  exerted 
transversely  and  the  farther  it  is  exerted  from  the  base,  the  greater 
the  tendency  for  fracture.  Of  course,  when  force  is  applied 
absolutely  in  the  axis  of  the  fiUing,  the  distance  from  the  base, 
theoretically,  makes  no  difference,  as  there  is  no  tensile  strain 
put  on  either  side. 

Dr.  Jenkins'  tests^  proved  that  pieces  of  porcelain  i  cm. 
square  by  2.3  mm.  deep  can  stand  a  steady  pressure  of  from 
J  ton  for  the  Whiteley  to  i  ton  for  the  Jenkins  porcelain,  the  others 
falling  somewhere  within  the  intervening  f  ton.  Dr.  Jenkins 
teUs  us  of  the  German  laboratory  in  which  these  results  were 
obtained  and  how  long  it  took  to  make  them,  but  does  not  tell 
us  how  they  were  made.  I  feel,  however,  that  this  great  pressure 
resistance  could  only  have  been  obtained  under  the  most  perfect 
^Cosmos,  May,  1902. 


156 


MODERN  DENTISTRY 


conditions,  where  there  was  pure  compression  without  percussion 
or  shear.  However,  if  we  could  approximate  these  conditions  in 
the  mouth,  most  of  us  would  be  satisfied  with  the  Whiteley  J-ton 
resistance,  as  it  is  not  likely  that  the  human  jaw  would  care  to 
tax  itself  more  than  that. 

So  much  for  steady  compression.     On  this  point,  obviously 
all  porcelains  are  able  to  take  care  of  themselves.     We  must. 


Fig.  79. — Instrument  for  measuring  shearing  strength  of  porcelain. 


then,  look  to  shear  and  percussion  for  the  weak  points.  First, 
let  us  consider  the  effects  of  shear.  For  this  purpose  we  have  a 
bar  of  porcelain,  0.075  ^y  0.125  inch,  cemented  into  a  block  of 
ivory  and  projecting  perpendicularly  from  its  surface.  These 
dimensions  were  chosen  because  they  were  felt  to  be  safely  above 
the  average  size  of  any  porcelain  tip  or  corner,  and  yet  to  fairly 


FILLINGS  157 

well  approximate  the  conditions  in  the  mouth.  The  porcelains, 
unless  otherwise  stated,  were  fused  on  platinum  and  afterward 
cut  to  the  proper  dimensions  on  a  carborundum  wheel.  They 
were  identical,  according  to  the  Brown  &  Sharpe  gage,  within 
o.ooi  inch.  Three  separate  instruments  for  measuring  the  shear 
had  to  be  made  before  friction,  jam  and  variations  in  the  pull 
were  successfully  eliminated.  Finally  this  simple  apparatus 
was  devised  (Fig.  79) :  A  represents  a  block  of  ivory  with  a  smooth, 
flat  surface;  B  represents  the  porcelain  bar,  0.075  by  0.125 
inch  cemented  into  the  ivory  block,  A,  at  right  angles  to  the 
smooth  surface;  C  represents  a  second  block  of  ivory  with  a 
smooth,  flat  face  terminating  in  a  knife  edge.  Block  A  was 
screwed  into  a  vise,  so  that  its  smooth  face  was  absolutely 
perpendicular.  The  smooth  surfaces  of  A  and  C  were  placed 
in  apposition,  with  the  knife-edge  of  C  resting  on  the  base  of 
the  projecting  porcelain,  B.  A  bucket  for  weights  was  attached 
in  such  a  way  as  to  bring  the  vertical  line  of  force  in  the  coinci- 
dent planes  of  A  and  C  exactly  at  the  base  of  the  porcelain  bar. 
Fine  shot  was  slowly  and  steadily  poured  into  the  bucket  until 
the  porcelain  snapped.  The  shot,  bucket,  and  block  C  were 
weighed  and  the  result  noted.  Block  A  was  then  removed  from 
the  vise;  the  remaining  bit  of  porcelain  was  crushed  by  a  small 
punch,  reamed  out  with  a  drill,  and  another  bar  of  porcelain 
cemented  into  position.     The  procedure  was  then  repeated. 

The  inlay  porcelains  tested  in  this  way  were  Jenkins', 
Brewster's,  Whiteley's,  and  S.  S.  White's. 

The  Jenkins  inlay  material  obtained  in  1900  stood  23,  36, 
27,  16,  33,  23,  23  pounds;  average,  26  pounds. 

The  Jenkins  improved  inlay  material  stood  16,  14,  16,  15, 
13  pounds;  average,  15  pounds. 

The  Whiteley  stood  28,  21,  19,  19,  18,  19  pounds;  average, 
21  pounds. 

The  Brewster  stood  15,  20,  18,  23,  19  pounds;  average,  19 
pounds. 

The  S.  S.  White  stood  29,  24,  25,  24,  25  pounds;  average, 
26  pounds. 

Experiments  were  made  on  bars  cut  from  blocks  of  molded 


158  MODERN  DENTISTRY 

porcelain  made  respectively  of  Whiteley  and  S.  S.  White  inlay 
materials,  resulting  in  the  following  figures:  S.  S.  White,  19 
and  20  pounds;  W^hiteley,  14  and  18  pounds.  In  these  tests 
the  compressed  porcelain  shows  less  strength  than  the  uncom- 
pressed. It  will  be  noted  that  the  Jenkins  improved  material 
had  much  less  shearing  strength  than  the  older  material,  which 
is  probably  due  to  the  fact  that  Jenkins'  improved  material 
made  a  better  filling  material  although  at  a  slight  sacrifice  of 
shearing  strength. 

It  was  then  determined  to  make  pressure  away  from  the  base 
of  the  bar  so  as  to  note  the  modifying  effect  of  leverage.  The 
ivory  block  C  was  cut  so  that  the  knife-edge  rested  on  the  porce- 
lain bar  0.075  iiich  out  from  its  base,  and  the  attachment  holding 
the  weight  was  adjusted  to  the  new  plane.  Experiments  showed 
that  porcelain  standing  26  pounds,  when  applied  at  the  base, 
now  broke  at  6  pounds,  demonstrating  what  a  tremendous 
difference  is  made  by  a  very  small  leverage.  Further  tests  were 
made  with  the  porcelain  bar  fastened  into  the  base  with  a  thin 
packing  of  rubber-dam,  and  it  was  found  that  such  a  springy 
base,  not  iinlike  the  peridental  membrane  around  a  tooth,  made 
no  difference  in  the  amount  of  direct  pressure  required  to  break 
the  bar. 

To  try  the  effect  of  a  percussion  blow  the  same  apparatus 
was  adjusted  horizontally,  and  instead  of  weights,  rubber  bands 
were  used  to  give  the  blow  (Fig.  80) .  The  procedure  was  as  fol- 
lows: The  ivory  block  holding  the  bar  of  porcelain  was  sunk 
into  an  oak  board  to  make  a  secure  foundation.  The  plane 
surface  in  which  the  porcelain  bars  were  to  be  cemented  was 
parallel  and  true  with  the  surface  of  the  board.  Nails  at  small 
intervals  were  driven  into  the  board  for  attachments  for  rubber 
bands,  which  when  attached  to  the  2-ounce  ivory  wedge  would 
snap  it  through  a  distance  of  |  or  |  inch  before  it  hit  the  porcelain 
bar.  The  force  of  the  rubber  bands  was  so  arranged  as  to  draw  the 
ivory  wedge  perfectly  true  along  the  surface  of  the  ivory  before 
it  struck  the  base  of  the  perpendicular  porcelain  bar.  After  the 
porcelain  broke,  the  pull  of  the  rubber  was  measured  by  a  spring 
balance.    The  distance  that  the  plunger  was  held  from  the  porce- 


FILLINGS 


159 


lain  was  controlled  by  a  small  loop  of  twine  fastened  from  the 
head  of  the  plunger  to  a  nail  driven  into  the  wood  at  a  suitable 
place.  It  was  found  that  perpendicular  bars  of  porcelain  hit  by 
the  2 -ounce  plunger  through  a  distance  of  |  inch  broke  at  a 
ridiculously  low  figure. 

With  blows  through  j  inch,  a  bar  of  Jenkins'  old  material, 
cemented  into  the  ivory  surface,  broke  at  6,  8,  7,  5,  5,  5  ounces; 
average,  6  ounces. 

Jenkins'  new  material  broke  at  8,  9,  8,  9,  8  ounces;  average, 

8.4  ounces. 

Whiteley's  broke  at  7,  8,  9,  10,  7,  6  ounces;  average,  8  ounces. 
Bars  from  Brewster  body  broke  at  6,  5,  6,  5  ounces;  average, 

5.5  ounces. 


Fig.  80. — Instrument  for  measuring  the  strength  of  porcelain  under  percussion. 


Bars  from  an  old  S.  S,  White  porcelain  tooth  broke  at  5,  5, 
6,  5  ounces;  average,  5  ounces. 

The  S.  S.  White  bars  made  from  compressed  porcelain  broke 
at  5,  6,  5,  6  ounces;  average,  5.5  ounces. 

The  author  does  not  care  to  make  any  general  deductions 
from  these  figures,  but  it  is  interesting  to  note  that  in  general 
the  porcelain  that  stood  the  least  shearing  force  had  the  greatest 
percussion  strength.  Also  that  the  compressed  porcelain  seemed 
to  have  less  percussion  strength  and  less  resistance  to  shear  than 
porcelain  made  without  compression.  AU  of  these  bars  of  porce- 
lain, when  surrounded  by  rubber-dam  instead  of  cement  in  the 
ivory  base,  broke  at  14  to  16  ounces,  indicating  that  with  per- 


l6o  MODERN  DENTISTRY 

cussion  blows  the  spring  of  the  peridental  membrane  undoubtedly 
greatly  increases  the  force  required  to  break  porcelain. 

Now  as  to  the  effect  of  percussion  on  the  surface  of  a  simple 
porcelain  inlay.  The  machine  for  testing  was  as  follows :  A  j-inch 
square  filling  of  Jenkins'  inlay  material,  o.i  inch  deep,  was 
cemented  into  a  block  of  ivory.  The  sides  were  parallel  and 
perpendicular  to  the  surface  of  the  ivory.  The  block  of  ivory 
was  screwed  into  a  board  so  that  the  side  containing  the  filling 
was  perpendicular  to  the  board.  Then  a  brass  plunger,  headed 
with  a  lower  bicuspid  tooth,  was  projected  by  means  of  rubber 
bands  against  the  filling  through  a  distance  of  I  and  |  inch 
respectively.  The  strength  of  the  pull  of  the  rubber  bands 
was  measured  by  scales  fastened  to  the  back  of  the  plunger. 
The  results  obtained  were  as  follows:  The  edge  was  sKghtly 
powdered  at  the  first  5-ounce  blow;  at  the  third  5-ounce  blow 
a  crack  ran  across  the  corner.  This  block  of  porcelain,  the  corner 
of  which  was  fractured  by  a  5-ounce  blow,  was  thicker  than  the 
block  of  porcelain  of  the  same  material  claimed  by  Dr.  Jenkins 
to  have  stood  a  steady  pressure  of  2020  pounds.  This  corner 
began  to  be  powdered  at  the  fourth  lo-ounce  blow.  These 
blows  were  all  through  a  distance  of  I  inch.  The  same  blows 
were  given  through  |  inch,  and  it  was  found  that  it  took  7  ounces 
to  chip  the  edge.  Another  corner  was  tried,  and  it  took  i-pound 
blows  to  break  the  corner,  delivered  through  I  inch. 

The  experiment  was  then  tried  of  cutting  a  corner  free  from 
the  cement  and  ivory,  leaving  it  supported  beneath,  about  as  a 
corner  of  a  tooth  would  be.  The  first  5-ounce  blow  chipped  it 
off  a  little  and  a  22-ounce  blow  was  required  to  break  it  off 
entirely.  This  test  seemed  to  prove  conclusively  that  porcelain 
cannot  withstand  the  full  percussive  force  of  the  teeth.  It 
apparently  can  stand  this  force  and  more  under  steady  pressure, 
especially  as  this  force  is  usually  appHed  through  the  inter- 
vening medium  of  food,  but  we  must  accept  the  fact  that  no 
porcelain  has  yet  been  made  that  can  withstand  the  ordinary 
percussive  force  that  during  mastication  may  at  any  time  be 
developed.  Fillings,  therefore,  must  be  rounded  so  as  to 
receive  glancing  blows,  the  edges  must  be  kept  as  free  as  pos- 


FILLINGS  l6l 

sible  from  strain,  and  if  they  chip,  the  powdered  edge  should 
be  cut  out  with  a  fine  inverted  cone  bur  and  filled  with  silicious 
cement. 

The  author  has  not  gone  into  the  subject  of  the  specific  gravity 
of  porcelains,  for  he  has  not  been  able  to  find  that  it  has  any  par- 
ticular bearing  on  the  case.  In  fact,  glass,  which  is  porcelain 
fused  to  even  consistency,  according  to  Hovenstadt's  Jena  glass 
tests,  seems  to  resist  crushing  force  almost  inversely  propor- 
tional to  its  specific  gravity.  It  is  interesting  to  note  that  all 
the  thirty-five  glasses  tested  for  crushing  force  stood  from  seven 
to  fourteen  times  as  much  as  any  of  the  porcelains  tested  by 
Dr.  Jenkins.  It  is  also  of  interest  to  note  that  the  bars  of  com- 
pressed porcelain  of  S.  S.  White  and  Whitely  inlay  materials 
did  not  stand  as  great  a  test  as  bars  of  the  same  material  molded 
in  the  ordinary  way  without  pressure,  seeming  to  show  again 
that  great  density  is  not  necessarily  a  factor  that  makes  for 
strength  in  withstanding  the  force  of  mastication. 

These  facts  seem  to  point  to  the  following  conclusions:  AU 
of  the  standard  porcelains  in  the  market  are,  for  practical  pur- 
poses, equally  strong,  but  none  of  them  are  strong  enough  to 
receive  the  full  force  of  mastication.  So  the  question  resolves 
itself  into  which  porcelain  has  the  best  colors  and  which  is  most 
easily  manipulated. 

The  Porcelain  Inlay  Matrix. — In  1887  Dr.  C.  H.  Land  made 
mechanically  perfect  edges  possible  for  intricate  porcelain  inlays 
by  devising  the  metal  matrix.  He  made  use  of  both  gold  and 
platinum  matrices,  but  found  the  latter  preferable,  as  platinum 
could  be  adapted  with  a  facihty  equal  to  gold,  and  allowed  the 
use  of  a  high-fusing  porcelain  body  that  insured  insolubihty 
as  well  as  giving  the  most  life-like  reproduction  of  the  color  of 
the  tooth  to  be  repaired.  From  this  discovery  dates  all  effective 
porcelain  filling.  Before  this,  pieces  of  porcelain  had  been  ground 
to  fit  labial  cavities  with  fairly  good  results,  and  pieces  of  natural 
enamel  from  extracted  teeth  had  been  inserted  in  a  similar 
manner,  but  the  accurate  adaptation  of  porcelain  to  approximal 
or  compound  cavities  was  practically  impossible  until  the  metal 
matrix  was  evolved.     Some  men  still  use  a  porcelain  that  can 


l62 


MODERN   DENTISTRY 


be  fused  upon  gold,  but  the  higher-fusing  porcelain  requiring  a 
platinum  matrix  gives  more  consistent  and  better  results. 

Construction  of  a  Porcelain  Inlay. — The  cavities  should  be 
free  from  undercuts.  If  these  are  unavoidable  through  extensive 
decay,  the  cavity  should  first  be  filled  with  phosphate  of  zinc, 
then  shaped  into  a  perfect  cup  with  a  flat  bottom.  The  edges 
should  be  sharp  and  smooth,  and  where  they  are  approximal 
there  must  be  suflicient  separation  to  allow  the  metallic  material 
in  which  the  porcelain  is  to  be  fused  to  be  withdrawn  without 
distortion.  The  final  polishing  of  the  edges  of  the  cavity  can  be 
done  with  a  small  carborundum  stone,  which  can  be  carved  to 
any  shape  and  size  with  a  diamond  point.  A  finishing  bur  is  also 
excellent  for  this  purpose,  as  is  also  a  sand-paper  engine  disk. 


Fig.  8i. — Cavities  formerly  filled  with  gold  or  porcelain- — now  advantageously- 
filled  with  silicious  cement. 


The  silicious  cements  have  so  far  replaced  the  insertion  of 
porcelain  in  simple  labial  or  buccal  cavities,  as  in  Fig.  8i,  that 
there  is  not  one  inserted  now  where  there  used  to  be  a  hundred ; 
and  yet  there  are  cases  where  the  porcelain  can  be  used  with 
advantage,  for  example,  in  the  mouths  of  tobacco  smokers,  where 
the  cement  would  ordinarily  discolor.  Therefore  the  technic  of 
making  such  a  porcelain  filling  can  be  advantageously  included 
in  the  general  study  of  porcelain  inlays. 

Where  the  inlay  is  to  stand  the  force  of  mastication  the  edges 
of  the  cavity  should  be  at  right  angles  to  the  grinding  surface 
(Figs.  82  and  83).  Such  a  precaution  will  obviously  add  to 
the  permanency  of  the  filling,  as  it  provides  the  greatest  possible 
resistance  of  both  tooth  and  filling  to  the  strain  of  mastication. 


FILLINGS  163 

The  preparation  of  the  cavity  being  completed,  the  matrix  is  made 
with  rolled  platinum,  o.ooi  inch  in  thickness.  Foil  thinner  than 
0.00 1  inch  seems  to  lack  sufficient  body  to  stretch  properly  with- 
out tearing.  This  platinum  if  annealed  in  a  Bunsen  burner  or 
with  a  blow-pipe  will  be  harsh  and  unfit  for  use,  but  when 
annealed  in  an  electric  furnace  it  becomes  soft  and  tough.  It  is 
most  essential  that  the  platinum  be  absolutely  soft.  The  plati- 
num is  placed  over  the  cavity  and  pressed  with  spunk  or  bibulous 
paper  as  far  as  possible  without  tearing.  This  gives  us  the  great- 
est amount  of  metal  with  which  to  form  a  mold.  The  edges 
now  have  become  distinctly  outlined,  and  from  this  time  the 
platinum  must  be  held  absolutely  immovable  or  good  results 
cannot  be  obtained.     When   the  edges  have  become  outlined 


Fig.   82. — Correct  incisal  angle  for  a       Fig.  83. — Incorrect  incisal  angle  for  a 
porcelain  filling.  porcelain  filling. 

they  should  be  gone  over  carefully  with  ball  burnishers  (Fig. 
84,  d  and  b)  and  made  sharp  and  free  from  wrinkles,  the  metal 
being  spun  down  into  the  cavity  as  far  as  can  be  done  without 
danger  of  tearing.  Should  wrinkles  in  the  metal  occur  they  must 
be  smoothed  out  before  they  reach  the  edge  with  the  spatula 
shown  in  Fig.  84,  d.  Then  the  metal  should  be  boldly  swaged 
to  the  bottom  of  the  cavity  with  bibulous  paper  held  with  the 
pliers  (Fig.  84,  c).  This  can  usually  be  accomplished  without 
tearing  the  foil,  but  if  tears  do  occur  they  are  quite  harmless, 
as  they  cannot  extend  to  the  edge  where  the  foil  has  already 
been  adapted.  Where  the  labial  cavity  extends  under  the  gum 
a  larger  piece  of  foil,  held  immovable  well  up  on  the  gum  and 
swaged  down  on  the  cavity  with  bibulous  paper,  will  form  an 


164 


MODERN  DENTISTRY 


arch  that  presses  and  holds  the  gum  back,  so  that  in  cases  that 
at  first  seem  absolutely  hopeless  of  success  the  upper  margin 
of  the  cavity  will  be  clearly  defined. 

The  soft,  unburnished  platinum  takes  a  beautiful  in  pres- 
sion,  but  when  the  metal  has  been  burnished  or  swaged  it  be- 


a  b  c  d 

Fig.  84. — Instruments  useful  for  forming  a  matrix. 


comes  elastic.  If,  therefore,  the  matrix  be  moved  during  its 
formation  an  accurate  impression  is  practically  impossible, 
for  the  elastic  platinum  when  distorted,  cannot  be  forced  back 
accurately  into  position  until  it  has  been  re-annealed.  The 
matrix  when  finished  should  be  carefully  heated  to  redness  in 
order  to  render  it  sterile.    In  labial  cavities  the  piece  of  platinum 


FILLINGS  165 

should  be  cut  sufficiently  large  to  extend  beyond  the  two  ad- 
jacent teeth,  and  the  metal  should  be  moulded  to  the  three  teeth 


Fig.  85. — Position  of  instrument  and  fingers  in  burnishing  a  matrix  into  place  on 
upper  incisors  or  canines. 

by  pressure  with  cotton  and  bibulous  paper.  The  metal  is  then 
held  firmly  upon  the  two  adjacent  teeth  by  the  first  and  second 
fingers,  as  in  Fig.  85,  when  the  general  directions  for  adjusting 


Fig.  86. — Position  of  fingers  in  forming  a  matrix  to  cavity  in  incisal  corner  of  an 

incisor. 

the  matrix  to  the  cavity  may  be  readily  carried  out.    The  large 
piece  of  platinum  has  two  great  advantages — it  conduces   to 


i66 


MODERN   DENTISTRY 


Fig.  87. — Position  of  hands  in  forming  a  matrix  for  a  compound  cavity  on  the 
anterior  approximal  surface  of  a  left  upper  molar. 


Fig.  88. — Position  of  fingers  in  forming  a  matrix  for  the  compound  approximal 
cavity  in  the  posterior  surface  of  an  upper  bicuspid  or  molar. 


immobility  of  the  metal  during  the  formation  of  the  matrix, 
and  it  gives  the  entire  labial  form  of  the  tooth,  so  that  an  accurate 
idea  may  be  obtained  of  the  desired  contour  of  the  filling. 


FILLINGS  167 

In  corners  of  centrals,  as  in  Fig.  86,  the  platinum  should  be 
folded  well  over  the  labial  and  lingual  surfaces  of  the  teeth,  then 
it  should  also  be  bent  over  the  cutting  edge,  forming  a  cap  beneath 
which  shows  the  entire  contour  of  the  tooth,  and  by  means  of 
which  entire  immobility  may  be  obtained  while  the  cavity  margins 
are  being  defined  and  the  matrix  formed.  The  same  principle 
applies  in  forming  a  half  cap  from  a  large  piece  of  platinum  for 


Fig.  89. — Method  of  splitting  platinum  matrix  near  the  impression  of  the 
cavity  in  order  to  facilitate  easy  removal  of  the  foil  through  a  narrow  space  without 
distortion. 


the  approximal  cavities  of  bicuspids  and  molars.  The  platinum 
should  extend,  as  in  Figs.  87  and  88,  from  grinding  edges  to 
cervical  margin,  and  along  the  adjacent  sides  of  the  tooth.  This 
can  be  firmly  held  with  the  index-finger  and  thumb  of  the  left 
hand,  while  the  right  hand  with  tweezers  and  bibulous  paper 
presses  the  metal  partly  into  the  cavity.  The  margins  and  floor 
of  the  matrix  may  then  be  defined  with  a  burnisher.    It  is  most 


1 68  MODERN  DENTISTRY 

important  that  the  greater  part  of  the  grinding  surface  of  the 
tooth  shall  be  outKned  in  making  the  mold,  as  by  this  means 
a  truss  effect  is  produced  that  will  prevent  the  distortion  of  the 
sides  of  the  matrix,  both  when  it  is  taken  off  the  tooth  and  when 
the  porcelain  is  being  fused.  In  mesial  cavities  the  metal  must 
be  pushed  away  from  the  operator  and  the  matrix  held  by  means 


Fig.  go. — An  excellent  device  for  holding  metal  immovable  while  being  burnished 

into  position. 

of  the  thumb  and  forefinger,  as  in  Fig.  87.  In  distal  cavities 
the  metal  is  pulled  toward  the  operator,  who  works  around  and 
beyond  the  fingers  holding  the  platinum  as  in  Fig.  88.  When,  as 
sometimes  occurs,  the  adapted  platinum  is  dove-tailed  around 
the  teeth  so  as  to  render  its  removal  difficult  or  impossible  without 
distortion,  the  outer  edge  of  the  platinum  may  be  split  with  a 
sharp  knife  from  the  gum  line  to  a  point  just  beyond  the  cavity 


FILLINGS  169 

margins,  as  is  shown  in  Fig.  89.  Figure  90  shows  a  method  of 
obtaining  immobihty  of  the  matrix  by  a  clamp  that  is  sometimes 
useful.    Figures  91  and  92  show  the  position  of  the  fingers  when 


Fig.  91.— Position  of  fingers  in  holding  the  foil  while  matrix  is  being  formed  on 
lower  right  side  of  jaw. 

manipulating  the  matrix  on  the  lower  teeth.  This,  as  before 
stated,  should  be  done  while  the  matrix  is  held  motionless  in  the 
cavity.    It  is  sometimes  advisable,  in  order  that  perfect  immo- 


Fig.  92.— Position  of  fingers  in  holding  foil  while  matrix  is  being  spun  into  cavity 
on  lower  left  side  of  jaw. 

bihty  may  be  obtained  during  the  final  burnishing  of  the  margins, 
to  re-anneal  the  matrix  just  before  its  completion,  and  then 
after  its  replacement  to  pack  it  full  of  cotton  or  bibulous  paper, 


170  MODERN  DENTISTRY 

leaving  the  edges  exposed  to  the  unrestricted  action  of  the  bur- 
nisher. When  this  has  been  done  and  the  packing  removed  there 
will  be  no  difficulty  in  teasing  out  an  undistorted  matrix  from 
the  cavity. 

Color  Selection. — The  color  of  the  filHng  must  next  be  con- 
sidered. This  is  one  of  the  most  important  steps  in  the  entire 
operation,  and  while  the  accuracy  of  selection  must  ultimately 
rest  with  the  color  sense  of  the  operator,  there  are  nevertheless 
a  few  fundamental  rules  that  will  be  of  material  assistance. 
There  are  two  great  factors  that  must  be  solved  if  a  porcelain 
filling  is  to  accurately  match  the  tooth  into  which  it  is  inserted: 
first,  the  proper  color  must  be  decided  upon  by  means  of  a  sample 
piece  of  porcelain  on  a  shade  ring;  second,  that  porcelain  must 
be  accurately  reproduced  by  a  judicious  mixing  of  the  basal 
porcelain  shades  and  by  accurate  baking.  The  question  of  de- 
ciding on  a  color  is  not  a  mere  question  of  matching  the  tooth, 
but  of  deciding  on  the  porcelain  that  will  match  the  tooth  per- 
fectly after  the  porcelain  is  cemented  into  position.  An  inlay 
may  match  a  tooth  perfectly  before  it  is  cemented  into  place, 
and  afterward  be  hopelessly  off  color,  and  the  reverse  is  also  true. 
Many  times  the  porcelain  filHng  that  does  not  match  at  all  out 
of  the  mouth,  when  it  is  cemented  into  position  will  melt  out 
of  sight  and  become  invisible.  In  plain  words,  the  shadow 
cast  by  the  cement  that  holds  the  inlay  in  position,  or  the  shadow 
cast  by  the  tooth  walls  modifies  the  color  of  the  inlay  in  an 
astonishing  degree.  Therefore,  in  addition  to  the  classification 
— ^labial,  buccal,  approximal,  contour,  etc. — ^porcelain  fillings 
are  to  be  considered  in  regard  to  their  positions  in  the  mouth,  viz., 
fillings  that  keep  their  color  when  cemented  into  place  and  those 
that  will  be  darkened  by  consequent  shadow.  The  color  of  a 
porcelain  fiUing  is  dependent  upon  the  perfection  with  which 
the  light  is  reflected  to  the  eye  of  the  observer.  In  a  bright, 
direct  light  yellow  porcelain  is  yellow  because  all  the  other  rays 
that  make  up  the  light  are  absorbed  and  only  the  yellow  are 
reflected.  If  the  light  be  gradually  decreased,  fewer  yeUow  rays 
will  be  reflected  and  the  color  will  become  darker.  When  there 
is  no  light  the  porcelain  will  appear  black.    Take,  for  instance,  a 


FILLINGS 


171 


simple  labial  cavity,  as  illustrated  in  Fig.  93.  If  this  extends 
into  the  dentin  sufficiently  deep  to  prevent  the  color  of  the  cement 
from  shining  through  it,  and  the  porcelain  is  not  overbaked,  the 
true  color  of  the  porcelain  will  be  given.  This  is  especially  so 
when  the  modern  silicious  cements  are  used  for  a  binding.  With 
the  old  opaque  phosphate  cement  it  was  always  an  approximate 
match,  "good  if  one  didn't  look  at  it  too  hard."  In  Fig.  94  the 
fillings  go  straight  through  the  labial  and  palatal  walls  of  the 
enamel,  and  yet,  if  both  fillings  are  made  of  porcelain  that  matches 
the  tooth  substance,  the  corner  inlay  when  cemented  into  position 
will  look  well,  while  the  half-moon  shaped  filling  will  look  dark. 
If,  however,  the  moon-shaped  filling  does  not  go  through  the 


Fig.  93. — Porcelain  inlay  where  color 
of  tooth  is  easily  matched. 


Fig.  94. — C,  Easy  to  match;  D,  difficult 
to  match. 


lingual  waU  and  the  cement  extends  entirely  behind  it,  its  color 
will  be  nearly  if  not  quite  as  good  as  that  of  the  corner.  The 
difference  of  the  shade  of  these  two  fillings  may  be  explained  as 
follows:  the  corner  C  is  illuminated  by  the  side  light  from  the  cut- 
ting edge,  while  the  half -moon  shaped  filling  D  is  shut  in  on  four 
sides,  on  three  by  cement  and  on  the  fourth  by  the  adjacent 
tooth.  With  D  the  light  passes  through  the  porcelain  with  a  great 
loss  of  reflection  and  with  a  loss  of  Kght,  while  with  C  the  side 
light  brings  out  the  color.  It  must  be  further  noted,  with  refer- 
ence to  the  corner  C,  that  if  it  is  looked  at  directly  from  in  front 
or  from  the  direction  of  the  arrow  B  toward  the  cement,  the  color 
will  be  good.    If,  however,  it  is  looked  at  away  from  the  cement, 


172  MODERN  DENTISTRY 

as  indicated  by  the  arrow  A,  the  color  will  be  lighter  or  darker 
according  to  the  intensity  of  the  Ught.  This,  however,  is  much 
less  apparent  since  the  translucent  siHcious  cements  have  become 
available.  It  should  therefore  be  easy  to  obtain  a  good  color  in  a 
corner  inlay.  Buccal  fillings  in  bicuspids  and  molars  are  as  easily 
matched  as  simple  labial  cavities,  for  they  come  under  the  same 
condition  of  Hght  reflection.  Cervical  fillings  that  extend  to  or 
imder  the  gum  are  affected  by  the  shadow  of  the  gum,  and  all 
approximal  inlays  from  the  posterior  surface  of  the  canines  back 
through  the  molars  show  the  same  falKng  off  in  color,  and  unless 
proper  allowance  is  made  for  this,  disheartening  results  will  be 
the  outcome  of  otherwise  careful  work.  There  will  be  a  darken- 
ing of  the  inlay  in  direct  proportion  as  the  cement  shuts  off  the 
light  and  throws  a  shadow  into  the  body  of  the  porcelain,  which 
shadow  can  be  overcome  to  a  certain  extent  by  the  judicious 
addition  of  yellow. 

It  will  be  found  where  a  siHcious  cement  filling  is  used  instead 
of  porcelain  that  the  same  law  holds,  and  that  a  judicious  modi- 
fication in  color  must  be  made  if  a  good  match  is  to  be  obtained. 
Those  fillings  not  materially  affected  by  shadow  are  simple  labial 
cavities,  corners  and  tips  of  central  and  lateral  incisors,  and  the 
cusps  of  canines  and  bicuspids.  Those  most  affected  are  posterior 
cavities  in  canines,  bicuspids,  and  molars. 

There  are  a  few  principles  that  wiU  be  a  guide  in  combating 
this  change  of  color.  The  shadow  casts  a  blue  into  the  filling,  or, 
at  least,  if  that  is  not  correct  from  the  law  of  physics,  blue  added 
to  a  filling  will  increase  the  shadow  effect  and  yellow  will  counter- 
act it.  I  shall  give  as  an  illustration  an  experience  of  my  early 
days  in  porcelain.  I  wished  to  insert  an  inlay  in  the  posterior 
surface  of  a  canine,  as  in  Fig.  95,  that  had  a  Hght  yellowish-blue 
color.  I  tried  matching  the  tooth  accurately  and  when  the  inlay 
was  cemented  into  place  it  looked  like  a  piece  of  gray  mud.  It 
was  taken  out,  and  after  several  trials  I  decided  to  make  the 
next  inlay,  if  anything,  too  yeUow.  So  a  fiUing  of  light  chrome 
yeUow  was  made  and  when  cemented  into  place,  it  turned  exactly 
the  color  of  the  tooth,  Hght  yeUowish  blue.  So,  in  cavities 
between  teeth  where  the  depth  and  cavity  waUs  wiU  cause  but 


96a 


96b 


97a  97b 

Figs.  96a,  96b. — Porcelain  inlays  shown  by  the  dotted  line  and  the  yellow 
spot.  These  inlays  have  their  respective  colors  when  the  light  is  thrown  directly 
upon  them  from  a  perpendicular  axis,  but  when  the  light  is  thrown  from  the  side, 
as  in  Figs.  97a  and  97b,  the  formerly  perfectly  matched  filling  of  96a  appears 
dark  and  the  formerly  yellow  filling  of  96b  modified  by  the  shadow  of  the  cement 
and  cavity  walls  becomes  a  perfect  match  with  the  tooth  color. 


FILLINGS  173 

little  shadow,  the  use  of  light  yellow  is  a  valuable  aid  in  counter- 
acting the  color  change;  but  when  the  inlay  represents  a  bad 
case  of  shadow  to  be  overcome,  deep  yellow  should  be  used  and 
marvelous  matches  will  sometimes  be  achieved — matches  that 
seem  like  the  work  of  necromancy  (Fig.  96).  For  instance,  we 
here  have  two  sound  bicuspids  with  simple  buccal  cavities  which 
have  been  filled  with  porcelain  inlays.  The  color  of  the  teeth 
in  each  instance  is  Hght  yellowish  gray,  as  is  shown  by  the  illus- 
tration. The  illuminating  hght  in  this  instance  is  supposed  to 
come  from  the  front,  where  each  filling  will  get  direct  Hght  and 
reflection.  It  will  be  noted  that  while  the  filling  in  ^  is  a  perfect 
match,  the  filKng  in  -S  is  a  decided  yel- 
low. This  light  reflection  gives  the  fill- 
ings their  genuine  color  values.  If, 
however,  the  light  comes  in  the  direction 
of  the  arrow  and  the  cavity  walls  and 
cement  thus  cast  a  shadow  (Fig.  97), 
it  will  be  found  that  the  supposedly 
well-matched  filHng  in  A  becomes  a 
dark  spot,  while  the  filHng  in  B  matches,  Fig.  95. -Posterior  por- 

the  yellow  fading  into   Hght  yellowish     ^f  7ell^w  ^Jll'countemTt 
gray.     With   the   tooth   B   the   yeUow     shadow. 
will    have    to    be    added  in    sufficient 

quantity.  If  there  is  not  enough  shadow  the  filling  will  still 
be  yellow;  if  there  is  too  much  shadow  even  the  yellow  fiUing 
will  be  dark. 

The  same  principle  appHes  in  the  mixing  of  cements,  espec- 
ially the  siHcious  cements.  In  matching  the  teeth  the  author 
uses  only  three  colors — dark  yellow,  hght  yellow,  and  dark  bluish 
gray.  There  are,  of  course,  a  great  variety  of  colors  that  could 
be  obtained,  but  they  seldom  just  match  and  are  usually  a  com- 
promise: but  with  the  three  basal  colors  boldly  used  any  effect 
can  be  obtained,  and  the  author  strongly  advises  aU  young 
dentists  to  learn  to  mix  their  colors  from  the  basal  colors  rather 
than  to  depend  upon  the  selections  of  the  manufacturers.  The 
same  principle  appKes  even  more  strongly  in  the  mixing  of  the 
various  colors  in  porcelain  work,  for,  as  in  the  cements,  the 


174  MODERN  DENTISTRY 

various  manufacturers  of  porcelains  make  a  large  variety  of  mix- 
tures, hoping  to  relieve  the  dentist  of  the  artistic  responsibility  of 
mixing  his  own  colors.  It  is  as  though  a  professional  house 
painter  depended  upon  the  colors  that  were  to  be  had  in  sample 
cans,  and  never  trained  himself  to  actually  mix  the  fundamental 
colors  himself.  Such  a  painter,  among  his  fellows,  would  be 
considered  a  joke. 

There  is  but  one  set  of  porcelains,  to  my  knowledge,  that 
practically  overcomes  this  ridiculous  limitation.  It  is  the  porce- 
lain made  by  Whiteley,  with  the  shade  rings  (Fig.  98).  This 
set  consists  of  seven  fundamental  colors,  which,  when  variously 
mixed,  can  make  any  shade  in  the  shade  ring.  Not  only  are  the 
basal  colors  supplied,  but  also  a  table  stating  the  approximate 
proportions  in  which  these  colors  should  be  mixed  to  form  any 
shade.  The  set  also  provides  a  box  of  powdered  white  silex,  that, 
when  mixed  with  the  porcelain  in  the  proportion  of  i  to  5,  will 
reduce  the  shrinkage  so  that  a  filling  can  be  made  in  two  bakings 
rather  than  in  six  or  seven,  as  is  customary  with  other  makes  of 
porcelain.  The  silex  mixture  can  be  used  in  the  preHminary 
bakings,  but  the  final  baking  should  be  made  with  porcelain  that 
does  not  contain  the  silex,  as  the  silex  has  a  slightly  lightening 
effect,  which,  however,  is  not  sufficiently  marked  to  show  through 
and  affect  the  color  of  the  outside  coating  of  porcelain.  When 
the  various  shades  of  porcelain  have  been  selected  they  should 
be  mixed  together  on  a  clean  glass  slab  and  made  into  a  paste 
with  water.  The  standard  dryness  is  obtained  by  pressing  a 
muslin  napkin  or  a  piece  of  blotting-paper  upon  the  mixture 
until  it  has  the  consistence  of  dough.  If  the  silex  is  to  be  used, 
as  is  wise  in  the  larger  fiUings,  this  dough  should  be  divided  into 
two  portions  and  the  silex  thoroughly  mixed  with  one  portion, 
in  the  ratio  of  i  to  4  or  5  parts. 

Making  and  Baking  the  Filling. — ^We  are  now  ready  to  fill 
the  matrix  with  the  porcelain  dough.  This  should  be  done  as 
follows:  The  matrix  should  be  seized  with  a  pair  of  pHers  at 
such  a  portion  of  the  platinum  as  will  not  distort  or  infringe  on 
the  model  of  the  cavity,  and  then  a  portion  of  the  porcelain 
dough  should  be  placed  within  the  matrix  on  the  point  of  a  brush 


Fig.  98.  —A,  Seven  fundamenlal  colors  which,  judiciously  selected  and  mixed,  can 
reproduce  any  color  on  the  circular  shade  ring  below,  B. 


FILLINGS 


17: 


or  spatula  (Fig.  99)  and  settled  into  position  with  a  rub  of  the 
rough  handle  on  the  pliers  that  hold  the  platinum.  This  rubbing 
of  the  rough  handle  on  the  pliers  jostles  the  porcelain  particles 
closer  together  and  makes  them  float  in  the  water  of  the  dough, 
so  that  with  skilful  manipulation  the  porcelain  can  be  placed  in 
any  shape  or  position  desired.  More 
porcelain  paste  can  be  added  at  will 
until  it  comes  up  to  the  edges,  which 
should  be  kept  scrupulously  clean.  The 
making  of  the  contour  is  most  important 
and  is  one  of  the  great  tests  of  the  skill 
and  artistic  sense  of  the  porcelain  worker. 
After  the  filled  matrix  has  been  care- 
fully dried,  by  keeping  it  face  downward 
on  a  piece  of  soft  muslin,  it  is  placed 
at  the  door  of  an  electric  furnace,  care- 
fully dried  until  all  steam  stops  rising 
from  it,  and  then  it  is  placed  in  the 
oven  and  baked  until  a  gloss  appears. 
It  is  advisable  to  support  the  filled 
matrix  on  a  piece  of  platinum  to  pre- 
vent its  possible  adherence  to  the  floor 
of  the  furnace. 

The  baking  will  cause  the  porcelain 
to  shrink  about  one-fifth  of  its  bulk. 
The  partly  filled  matrix  must  then  be 
removed,  allowed  to  cool,  filled  once 
more  up  to  the  edges  with  porcelain, 
and  baked  again.  A  third  or  fourth 
baking  may  be  used  as  needed.  After 
the  baking  is  completed,  the  filling  may 
be  taken  from  the  furnace  almost  im- 
mediately, as  practically  only  very  large  pieces  need  to  be 
cooled  slowly,  although,  theoretically,  a  gradual  cooHng  will 
make  the  porcelain  tougher.  The  platinum  should  now  be 
stripped  off,  care  being  taken  to  pull  it  away  from  the  edge. 
Should  it  be  pulled  toward  the  edge,  chipping  is  likely  to  occur. 


Fig.  99. — Brush  and 
instrument  for  handling 
and  molding  porcelain 
paste. 


176  MODERN  DENTISTRY 

If  small  portions  of  platinum  stick  to  the  porcelain  they  can 
be  pulled  off  with  a  sharp-pointed,  tempered  instrument  or  a 
small,  sharp  engine  bur. 

In  large  or  difficult  cavities  a  double  burnishing  is  sometimes 
advisable.  The  procedure  is  as  follows:  The  first  addition  of 
the  porcelain  to  the  matrix  is  not  allowed  to  come  to  the  edge. 
This  is  baked  and  cooled.  The  matrix  is  put  again  accurately 
into  the  cavity,  held  immovable,  and  the  edges  reburnished. 

Inserting  the  Inlay. — Before  cementing  the  inlay  into  place, 
grooves  should  be  made  in  the  porcelain  by  using  a  thin  copper 
or  steel  disk  charged  with  diamond-dust  or  carborundum  powder 
(Fig.  100).  The  diamond-dust  is  incorporated  in  the  metal  by  a 
mechanical  process,  but  the  carborundum  is  used  as  a  paste, 
made  with  glycerin  or  cane  syrup,  in  which  the  disk  is  immersed 


Fig.  100. — Disk  charged  with  diamond-dust. 

before  the  cutting  of  the  porcelain  is  attempted.  The  diamond 
disk  is  more  easily  manipulated,  but  it  is  also  very  expensive  and 
wears  out  quickly,  while  the  loose  carborundum  and  revolving 
metal  disk  is  sharp  and  permanently  effective  for  all  but  the 
smallest  fillings.  It  is  well  not  to  mar  the  edges  of  the  fUHngs 
with  the  grooves,  but  this  is  not  now  as  great  an  injury  as  formerly, 
when  only  phosphate  of  zinc  cement  was  available.  If  there  is  a 
sHght  imperfection  in  the  margins,  well-selected  silicious  cement 
will  fill  it  so  as  to  make  it  quite  invisible.  The  disk  and  porcelain 
must  be  kept  thoroughly  wet  while  the  grooves  are  being  cut, 
and  the  grooves  should  be  as  deep  as  the  size  of  the  filhng  will 
permit,  so  as  to  allow  the  cement  to  enter  and  act  as  a  dowel  for 
the  attachment  of  the  inlay  to  the  tooth.  The  mere  adhesion  of 
the  cement  is  an  uncertain  quantity  and  should  not  be  depended 
upon  to  retain  the  filling  in  position.    For  instance,  in  Fig.  loi, 


FILLINGS 


177 


A  represents  the  filling  in  position ;  B  the  tooth  in  which  we  find 
the  cavity.  Such  a  filling  cemented  into  place  with  rough  sides 
would  be  only  moderately  secure,  but  if  the  inlay  and  tooth 
cavity  were  grooved  so  that  the  grooves  would  be  opposite 
each  other,  as  in  Fig.  102,  the  cement  would  act  as  a  pin,  holding 
the  inlay  in  position  in  the  tooth,  and  it  would  only  be  dislodged 
by  the  actual  breaking  of  the  cement.  Thus,  it  is  evident  that 
greater  stability  is  obtained  by  large  grooves  than  by  the  adhesion 


Fig.  loi. — Incorrect  and  insecure  method  of  securing  an  inlay  in  position, 
inlay  here  depends  upon  the  adhesion  of  cement  alone. 


The 


obtained  by  merely  roughening  the  inlay  and  cavity  walls.  In 
fact,  the  nearer  we  can  approximate  the  shape  of  a  collar-button 
in  shaping  the  inlay  for  retention,  the  greater  will  be  the  stability 
obtained.  While  the  grooves  are  being  cut  the  inlay  should  be 
held  so  that  the  edge  adjacent  to  the  intended  groove  may  be 
buried  in  the  skin  of  the  finger.  The  groove  can  then  be  fearlessly 
made  by  the  swiftly  revolving  metal  disk,  that  cuts  only  the  hard 
porcelain  and  pushes  back  the  yielding  tissue  of  the  finger  without 


Fig.  102. — Dowel  principle  of  holding  an  inlay  in  position  with  cement. 


inflicting  injury.  With  large  inlays,  where  there  is  plenty  of  room 
for  the  grooves,  carborundum  disks  are  most  useful.  If  the 
porcelain  is  blackened  by  the  disk  the  discoloration  may  be 
readily  removed  by  a  strong  jet  of  water  thrown  upon  it. 

The  method  of  inserting  the  inlay  is  as  follows:  The  fiJHng 
and  cavity  should  be  washed  in  alcohol  and  dried,  and  the  cavity 
protected  by  a  napkin  or  rubber-dam.  Silicious  cement  of  the 
proper  color  should  be  mixed  to  the  consistency  of  soft  dough 


178  MODERN  DENTISTRY 

and  placed  in  the  cavity,  and  the  inlay  picked  up  with  the  sticky 
spatula,  placed  in  position,  and  settled  home  by  a  tapping  motion 
that  will  rapidly  bring  the  inlay  into  position.  When  it  is  in  po- 
sition the  setting  of  the  cement  can  be  hastened  by  flowing  hot 
paraffin  upon  it.  This  setting  wiU  be  accomplished  in  a  minute 
or  two  so  that  the  patient  can  be  dismissed.  Wherever  it  is 
possible  it  is  well  to  leave  an  excess  of  cement  to  be  polished  off 
at  a  later  visit,  as,  theoretically,  the  more  thoroughly  the  cement 
is  protected  from  the  action  of  the  saliva  during  setting,  the  more 
perfect  the  results.  On  the  following  day  the  edges  may  be  ground 
with  an  Arkansas  stone  or  poHshed  with  sand-paper.  It  is  better 
for  finishing  that  the  edges  of  the  filling  should  be  a  little  below 
the  edges  of  the  cavity  rather  than  too  high.  If,  however,  the 
porcelain  is  too  high,  it  can  be  ground  down  and  still  give  good 
results,  but  the  original  gloss,  in  most  cases,  is  to  be  preferred. 

Cautions. — Having  described  the  general  operation  of  making 
and  putting  in  a  porcelain  filKng,  a  few  cautions  may  not  be  out 
of  place.  Overf using  is  one  of  the  great  causes  of  poor  colors, 
that  is  to  say,  the  porcelain  should  never  lose  its  amorphous 
consistency.  In  very  deep  cavities  a  bar  of  porcelain  extending 
through  the  bottom  of  the  matrix  makes  a  valuable  anchorage 
to  which  the  rest  of  the  porcelain  can  be  advantageously  added. 
In  large  contours  excessive  contraction  should  be  overcome  by 
adding  i  part  in  4  of  ground  silex  to  the  part  of  the  porcelain 
that  is  to  be  used  for  the  first  baking,  as  the  unfused  particles 
of  silex  extend  across  the  matrix  in  every  direction,  making  what 
is  practically  an  internal  investment.  When  handling  small 
fillings  the  pHers  and  cavity  may  be  advantageously  kept  wet 
up  to  the  time  of  insertion,  to  prevent  the  filHng  from  being 
dropped  and  lost.  To  place  a  tiny  filling  on  the  operating  case 
in  the  same  relative  position  that  it  will  take  in  the  tooth  pre- 
vents mistakes  as  to  which  side  should  go  in  first. 

There  are  three  classes  of  furnaces  that  can  be  used  for  fusing 
porcelains — gas,  gasoline,  and  electric.  The  gas  and  gasoline 
furnaces  are  noisy,  odorous,  and  dirty,  and  are  seldom  used  where 
electricity  is  available.  On  the  other  hand,  the  electric  furnace 
is  clean,  silent,  and  beautiful.     The  best  electric  furnace  for 


FILLINGS 


179 


porcelain,  in  the  author's  opinion,  is  the  Hammond  crown  furnace 
(Fig.  103).  It  is  so  constructed  that  if  a  muffle  burns  out  it  can 
be  at  once  replaced  by  a  new  one,  and  the  work  continued  with 
a  loss  of  not  more  than  fifteen  minutes.  The  various  gages 
for  telling  when  the  porcelain  is  fused  are  a  needless  expense. 
The  porcelain  worker  should  learn  to  fuse  porcelain  by  experience 
and  his  eye,  not  by  mechanical  appliances,  since  no  mechanical 
appliance  will  be  able  to  accurately  diflferentiate  the  relative 
time  required  to  fuse  a  small  filling,  a  crown  or  a  bridge.    Such 


Fig.  103. — Hammond  electric  furnace. 


appliances  tend  to  dwarf  the  natural  ability  of  the  porcelain 
worker  and  through  their  complexity  cause  a  great  waste  of 
valuable  time. 

The  gold  inlay  has  practically  perfect  edge  strength,  and 
therefore,  on  account  of  this  advantage  is  sometimes  to  be  pre- 
ferred to  the  porcelain  inlay.  This  is  especially  the  case  when 
the  filling  involves  a  large  contour  and  is  to  be  subjected  to  a 
great  stress  of  mastication.  It  also  has  the  great  advantage 
over  porcelain  of  being  capable  of  serving  as  an  abutment  for  a 


l8o  MODERN  DENTISTRY 

cantilever  bridge,  but  this  will  be  gone  into  more  particularly 
in  the  chapter  on  bridge  work. 

The  gold  inlay  is  easily  made  and  its  construction  ought  not 
to  take  over  ten  or  fifteen  minutes.  This  is  mentioned  because 
the  casting  methods  and  various  intricate  processes  recommended 
tend  to  make  it  a  long,  tedious,  uncertain  procedure.  These 
may  take  hours  if  not  days,  to  do,  with  uncertain  results,  that 
which  a  simple  method  can  accompKsh  in  a  few  minutes.  For 
instance,  a  simple  gold  inlay  in  the  buccal  surface  of  a  molar 
ought  not  to  take  over  five  minutes,  at  most,  to  complete  after 
the  cavity  is  prepared  along  the  lines  previously  stated,  that  is, 
cup  shaped,  with  sloping  sides  and  a  flat  bottom,  as  in  Fig.  104. 


Fig.  104. — Simple  cavity  prepared  for  gold  inlay:  A  represents  external  view; 
B  represents  cross-section. 

Soft  gold  plate,  bout  0.003  inch  in  thickness,  should  be 
held  immovable  over  the  cavity  with  the  fingers  and  burnished 
and  swaged  into  position,  forming  the  matrix.  Extra  immobility 
can  be  obtained  by  molding  the  gold  to  the  grinding  surface  of 
the  molar.  Then  moss  fiber  or  sponge  gold  should  be  firmly 
packed  into  the  gold  matrix  up  to  the  edges  of  the  cavity,  with 
large  pluggers.  If  the  matrix  gets  wet  during  the  process  no 
harm  results.  The  edges,  however,  should  be  kept  free  from 
the  moss  fiber  or  sponge  gold.  The  filled  matrix  should  then  be 
removed  and  22-karat  solder  flowed  into  it  by  adding  a  few 
grains  of  borax  and  squares  of  solder  and  holding  it  over  a  Bunsen 
burner  with  a  pair  of  pHers.  No  investment  is  necessary.  The 
filling  should  then  be  cut  out  of  the  gold  plate,  leaving  a  small 
margin  at  the  edges.    This  margin  is  later  polished  off  when  the 


FILLINGS 


l8l 


filling  is  cemented  into  place.  The  filling  and  cavity  can  then 
be  undercut,  as  previously  described,  and  the  filling  cemented 
into  place.  As  before  stated,  a  simple  cavity  hke  the  one  just 
described  would  not  now  be  filled  with  gold,  but  with  silicious 
cement.    The  process  has  been  described  to  show  the  simplicity 


Fig.  105. — A,  Lower  bicuspid;  B,  lower  molar;  C,  gold  inlay  to  be  constructed. 

of  the  moss  fiber  gold  matrix  method  in  comparison  with  the 
more  complicated,  intricate  casting  methods.  The  place  most 
suitable  for  a  gold  inlay  is  in  the  compound  approximal  cavity 
of  a  bicuspid  or  a  molar,  and  as  the  method  of  making  such  a  filling 
is  so  important,  it  will  be  given  in  detail. 


Fig.  1 06.- — Occlusal  view  of  Fig.  105. 

Let  us  take,  for  example,  an  inlay  for  a  large  cavity  in  the 
anterior  surface  of  a  first  lower  molar,  such  as  is  shown  in  Figs. 
105  and  106.  In  Fig.  105,  A  represents  the  bicuspid  against  which 
the  contour  of  the  filling  is  to  be  made.    B  represents  the  molar 


l82 


MODERN   DENTISTRY 


with  the  cavity  to  be  filled,  and  C  the  shape  of  the  completed 
inlay  in  position.  Figure  io6  represents  the  occlusal  aspect  of 
the  same  cavity.  In  Fig.  107  the  solid  lines  of  D  and  E  show  side 
and  three-quarter  views  of  completed  inlay.  This  is  the  type  of 
inlay  to  be  used  where  the  pulp  is  alive,  but  where  the  pulp  has 
been  removed  and  the  chamber  can  be  utilized  for  purposes 


Fig.  107. — Solid  lines  show  shape  of  inlay  for  Figs.  105,  106.  Dotted  lines 
show  projection  that  may  be  added  when  the  loss  of  pulp  gives  sufficient  space, 
as  in  Fig.  108. 

of  retention,  the  inlay  can  be  constructed  according  to  Fig.  108, 
which  is  self-explanatory.  The  only  point  of  interest  is  the  pro- 
jecting notch  of  the  inlay  that  extends  into  the  pulp  chamber, 
which  is  further  demonstrated  by  the  dotted  lines  in  Fig.  107. 
The  cavity  being  prepared  as  shown  in  Fig.  108,  with  sloping 
sides  and  sufficient  space  between  it  and  the  bicuspid  to  prevent 


Fig.  108. — Similar  to  Fig.  io6,  except  that  there  is  an  extra  depression  in  the  floor, 
permitting  greater  possibilities  of  retention  for  the  inlay. 

distortion  of  the  matrix  on  its  removal,  soft  gold  0.003  inch  in 
thickness  should  be  sHpped  in  between  the  bicuspid  and  the 
molar  so  that  it  will  project  well  beyond  the  lower  margin  of  the 
cavity  that  hes  next  to  the  gum.  Then  wet  bibulous  paper  should 
be  packed  in  between  the  teeth,  forcing  the  metal  well  into  the 


FILLINGS  183 

hollow  of  the  cavity.  This  should  be  done  before  the  gold  foil  is 
bent  to  the  contour  of  the  outside  of  the  tooth.  The  matrix 
should  then  be  removed,  the  gold  thoroughly  annealed  again, 
when  it  should  be  replaced  in  the  cavity  and  packed  firmly  with 
bibulous  paper  a  second  time.  Then  the  gold  plate  should  be 
folded  over  the  side  of  the  tooth  and  conformed  to  the  top  of 
the  tooth  so  that  it  assumes  the  shape  of  a  half-cap.  The  bibulous 
paper  should  then  be  removed  and  the  gold  burnished  and  spun 
into  all  parts  of  the  cavity  with  a  ball  burnisher.  There  will  be  no 
difl&culty  in  holding  the  gold  immovable  with  the  thumb  and 
forefinger  of  the  left  hand  while  this  is  being  accomplished. 
When  the  matrix  is  completed  a  mass  of  sponge  gold  should  be 
molded  somewhat  into  the  shape  of  a  wedge,  having  approxi- 
mately the  amount  of  gold  necessary  to  make  the  filling.  It 
should  be  shghtly  warmed  over  the  Bunsen  burner  to  make  it 
adhesive,  and  then  placed  within  the  matrix  while  the  matrix  is  in 
the  cavity.  Care  should  be  taken  to  allow  some  of  the  sponge  gold 
to  rest  and  infringe  upon  the  grinding  surface  of  the  adjacent 
bicuspid,  against  the  side  of  which  the  contour  of  the  inlay  must 
rest.  When  this  has  been  done  the  sponge  gold  must  be  firmly 
and  rapidly  condensed  into  place  with  large  broad  pluggers,  care 
being  taken  to  condense  it  thoroughly  against  the  contact  point 
of  the  bicuspid  wall  and  to  overlap  it  partly  on  the  grinding 
surface  of  the  bicuspid.  More  gold  can  be  added  if  necessary,  and 
in  a  short  while  a  large  gold  filKng  can  be  molded  into  the  proper 
bite  and  position.  The  gold  foil  and  filled  inlay  can  be  teased 
out  without  destroying  the  shape  of  the  inlay  and  the  whole 
filling  filled  with  22-karat  solder,  as  previously  described,  by 
soldering  it  over  a  Bunsen  burner.  If  the  gold  has  been  well  con- 
densed against  the  adjacent  wall  of  the  bicuspid,  and  the  solder 
is  not  placed  upon  the  exact  contact  point,  the  entire  inlay  can 
be  filled  solidly  with  solder  and  then  be  slipped  directly  back  into 
position,  giving  a  perfect  contact  with  the  bicuspid  and  making 
an  inlay  that  can  be  trimmed  and  polished  in  a  few  minutes. 
It  is  advisable  to  always  place  the  solder  on  the  grinding  surface, 
as  this  surface  will  generally  need  to  be  ground  in  any  case  in 
order  to  obtain  perfect  articulation. 


184  MODERN  DENTISTRY 

The  great  advantage  of  this  method  lies  in  the  fact  that  it  is 
so  easy  to  learn,  and  has  such  innumerable  possibilities  in  the 
ease  of  construction  of  half  crowns,  three-quarter  crowns,  com- 
plete crowns  with  facings,  and  cantilever  bridges;  but  all  of  these 
will  be  discussed  under  their  respective  headings.  I  was  once 
showing  a  graduate  class  the  method  of  making  the  filling,  just 
described,  on  a  model.  After  I  had  shown  them  once  or  twice 
how  to  make  the  inlay  (it  never  took  over  five  minutes)  one  of 
the  students  said,  "That  is  all  very  well  with  a  skilful  man,  but 
how  about  the  average  dentist?"  I  answered,  "Give  me  one 
of  your  average  students."  One  of  the  students  came  for- 
ward, and  I  said  to  him,  "Now,  do  just  as  I  say,  and  don't 
think  how  you  can  improve  my  method  before  you  learn  it." 
And  so,  under  instruction,  he  also  made  an  inlay  in  less  than 
five  minutes.  This  is  spoken  of  to  show  that  the  method  is  easy 
of  accompHshment  if  one  wiU  take  the  trouble  to  seriously 
attempt  it. 

Before  closing  the  subject  of  gold  inlays  it  might  be  said  that 
small  tears  at  the  bottom  of  the  matrix  are  of  little  consequence, 
as  the  gold  will  fiU  them  completely,  and  it  is  advisable  in  filling 
the  matrix  with  gold  not  to  let  the  gold  extend  over  the  matrix 
margins.  If  the  edges  are  kept  clean,  the  filling  will  be  more 
quickly  finished  and  inserted.  It  should  be  especially  remembered 
in  undercutting  the  filling  that  the  grooves  should  come  as  nearly 
as  possible  opposite  the  grooves  in  the  tooth  cavity,  so  that  the 
inlay  will  be  keyed  into  place  with  good,  strong,  rigid  cement 
dowels. 

Plastic  Fillings. — The  cement  question  has  been  so  much 
discussed  in  connection  with  inlays  that  it  might  be  of  value  to 
discuss  briefly  the  relative  merits  of  the  phosphate  of  zinc  cements 
and  the  silicious  cements. 

Phosphate  of  zinc  cement  is  valuable  inasmuch  as  it  appears 
to  be  more  adhesive  than  sihcious  cement.  It  is  therefore  useful  in 
cementing  on  attachments  to  the  teeth,  such  as  bands  for  ortho- 
dontia appliances,  crowns  and  bridges.  Its  adhesive,  tenacious 
quahty  makes  it  most  valuable  as  a  seal  for  the  retention  of 
antiseptic  dressings,  but  on  account  of  its  solubility  it  has  pal- 


FILLINGS  185 

pably  had  its  day  as  a  filling  designed  to  permanently  restore 
a  spot  of  decay.  Of  the  phosphate  of  zinc  cements,  the  Harvard 
cement  and  the  new  S.  S.  White  slow-setting  cement  are  the 
easiest  to  work  and,  on  account  of  being  more  slow  in  setting, 
give  the  best  results. 

The  silicious  cements,  as  before  stated,  are  capable  of  being 
mixed  to  absolutely  match  the  tooth  structure  to  be  replaced; 
they  are  quickly  inserted  and  are  insoluble.  Without  doubt 
they  represent  the  greatest  single  advance  the  mechanics  of 
dentistry  has  ever  known.  The  author  has  had  excellent  results 
with  both  the  Ames  sihcious  cement  and  the  synthetic  cement. 
Where  the  cement  powder  is  coarse,  as  is  the  case  with  the  syn- 
thetic cement,  a  very  thin  cement  Kne  can  be  obtained  by  cement- 
ing the  inlay  into  place  with  the  cement  mixed  to  the  consistency 
of  soft  dough,  and  then  placing  dry  powder  on  the  excess  that 
has  exuded  from  the  margins  of  the  cavity.  When  this  is  done 
the  heavier  granules  are  compressed  within  the  cavity  and  the 
more  liquid  portions  are  squeezed  out,  and  the  addition  of  the 
dry  powder  insures  a  perfect  cement  bond  on  the  edge.  There 
are  times,  however,  when  a  crown  or  inlay  must  largely  depend 
upon  the  adhesion  of  the  cement  for  its  retention,  and  under 
these  conditions  a  combination  of  phosphate  of  zinc  and  silicious 
cements  may  be  advantageously  used  as  a  retaining  bond.  The 
method  is  as  follows:  When  the  cavity  is  prepared  and  dried, 
the  silicious  cement  should  be  mixed  ready  for  use.  The  creamy 
Harvard  cement  should  then  be  rapidly  prepared  and  inserted 
as  a  cavity  Hning,  and  the  silicious  cement  immediately  placed  on 
the  inlay  or  crown  and  pushed  into  position,  forcing  out  all  excess 
phosphate  cement. 

Amalgam.— Before  the  cements  reached  their  present  strength 
and  beauty  amalgam  was  sometimes  used  as  a  bond  for  retaining 
inlays  in  place.  In  respect  to  strength  and  insolubility  it  was 
most  trustworthy,  but  its  color  tended  to  cause  a  shadow  in  the 
inlay,  that  it  was  almost  impossible  to  counteract,  and  the  dark 
edge  was  most  unsightly.  However,  since  we  are  dealing  with 
the  possible  bonds  for  inlays  it  might  seem  advisable  to  go  into 


1 86  MODERN   DENTISTRY 

the  methods  necessary  for  the  insertion  of  amalgam,  either  as  a 
cement  or  as  a  filling  material. 

Let  us  first  examine  the  philosophy  of  inserting  the  amalgam 
filling.  It  must  set  hard,  be  free  from  excess  mercury,  and  must 
have  a  bacteria-tight  margin.  A  bacteria-tight  margin,  not  a 
water-tight  margin,  for  a  water-tight  margin  around  a  non- 
adhesive  filling  in  a  moisture-soaked  tooth  is  as  much  of  an  im- 
possibihty  as  such  a  margin  would  be  in  a  wet  sponge.  There- 
fore, what  one  desires  to  obtain  is  a  bacteria-tight  filling,  and 
with  amalgam  it  makes  no  difference  whether  the  cavity  is  wet 
or  dry  if  only  it  be  kept  free  from  bacteria.  On  general  principles 
it  is  better  to  have  a  dry  cavity  than  a  wet  one,  but  the  main 
thing  with  the  insertion  of  amalgam  is  clean,  firm,  aseptic  edges. 
Then  if  a  cavity  whose  edges  extend  under  the  gums  is  flooded 
with  alcohol  or  some  other  appropriate  antiseptic,  and  this  anti- 
septic is  immediately  pushed  out  by  the  doughy  amalgam,  which 
amalgam  is  dried  of  its  excess  mercury  by  wafered  amalgam  or, 
better  stUl,  sponge  gold,  the  final  results  will  be  just  as  effective 
as  though  the  gums  had  been  jammed  away  from  the  root  by 
rubber-dam  or  a  matrix  and  the  cavity  dried  with  hot  air  prior  to 
the  insertion  of  the  filUng.  Since  amalgam  is  not  in  the  least 
adhesive  the  cavity  must  be  well  undercut  in  order  that  there  may 
be  good  dowel  retention.  The  old  method  of  mixing  amalgam 
powder  with  a  pestle  and  mortar  is  quite  obsolete.  The  best 
method,  in  the  author's  opinion,  is  to  put  the  desired  amount  of 
mercury  and  alloy  in  a  small-sized  test-tube.  The  finger  or 
thumb  should  then  be  placed  firmly  over  the  end  and  the  con- 
tents shaken  vigorously  for  a  minute,  at  the  end  of  which  time 
the  resulting  mixture  should  be  emptied  into  the  hand,  where  it 
can  be  easily  kneaded  with  a  few  rubs  of  the  thumb,  and  the 
material  will  be  ready  for  insertion.  The  formulae  recommended 
by  Black  and  Flagg  for  amalgam  have  given  continued  satis- 
faction in  the  author's  practice.  The  wafering  is  accomplished 
by  taking  some  of  the  excess  soft  amalgam  and  squeezing  it  in  a 
muslin  napkin  with  a  pair  of  pliers  until  all  excess  mercury  is 
forced  out.  The  resulting  wafer  is  then  added  to  the  soft  amalgam 
filling  by  means  of  a  spatula  moderately  heated.    The  mercury 


FILLINGS  187 

in  the  filling  will  be  sucked  out  into  the  substance  of  the  wafer, 
which  will  become  correspondingly  soft.     The  softened  wafer 
can  then  be  shaved  off  and  another  wafer  used,  or  the  excess 
mercury  in  the  first  wafer  can  be  squeezed  out  and  the  wafer 
appHed  again  and  again,  until  there  appears  to  be  no  excess  mer- 
cury in  the  filling.    After  this  it  is  well  to  tamp  the  filhng  into 
the  cavity  with  a  large  plugger  to  be  sure  that  all  the  space 
formerly  occupied  by  the  extracted  mercury  has  been  fully 
replaced  by  the  denser  amalgam.    This  should  be  accomplished 
by  a  tapping  motion  not  unlike  the  motion  used  for  setting 
porcelain  paste.    Amalgam  in  its  pasty  condition,  before  it  sets, 
is  similar  in  consistency  to  a  mixture  of  sand  and  water,  so  if 
it  is  merely  pushed  into  position  the  larger  particles  will  jamb 
on  each  other  and  large  unfilled  spaces  will  result.    But  if,  Hke 
the  porcelain  paste,  the  fiUing  is  tapped  and  jostled,  the  large 
particles  will  float  in  the  Hquid  mercury  and  come  in  closer 
approximation,  while  the  mercury  will  rise  to  the  surface,  as  the 
water  rises  to  the  surface  of  the  porcelain  dough  when  it  is  simi- 
larly jarred  for  the  purpose  of  condensation.     When  the  last 
tamping  has  been  accompHshed,  and  enough  of  the  wafer  added 
to  ensure  perfect  contours   and  edges,   sponge  gold,   slightly 
warmed  to  drive  off  any  free  moisture,  should  be  pressed  upon 
the  surface  of  the  fiUing  until  it  sticks.    The  patient  is  then  dis- 
missed.   If  the  gold  adheres  until  he  returns  it  can  be  polished 
off;  if  it  does  not  adhere,  it  means  that  there  was  no  excess  mer- 
cury.   In  either  case  the  result  is  a  dense  filling  inserted  quickly 
and  painlessly.    It  is  a  source  of  wonder  that  many  dentists  stiU 
work  amalgam  in  the  dry  state,  when  equal  if  not  better  results 
are  obtained  by  using  it  as  a  plastic. 

The  author  is  aware  that  the  use  of  a  piece  of  sponge  gold 
that  costs  from  twenty-five  cents  to  a  dollar.,  for  the  hardening 
of  an  amalgam  filHng,  will  seem  a  monstrous  extravagance  to 
many  dentists  who  would  rather  work  half  an  hour  or  even  an 
hour  longer  to  avoid  such  "wilful  waste,"  even  though  they  are 
working  over  a  sensitive,  suffering  patient. 

Amalgam  as  a  Cement.— When  an  anchorage  for  a  bridge  is 
to  be  made  in  an  amalgam  filling,  the  pin  or  gold  inlay  should 


1 88  MODERN  DENTISTRY 

be  inserted  into  the  mushy  amalgam  that  has  been  placed  in 
the  cavity.  The  pin  or  inlay  should  then  be  tapped  into  position 
until  it  settles  to  its  proper  level,  care  being  taken  that  vents 
have  been  made  on  the  edges  of  the  inlay  sufficiently  large  to 
allow  the  amalgam  grains  to  flow,  out  or  to  permit  of  tamping 
with  a  plugger  after  the  appHcation  of  amalgam  wafers  or  sponge 
gold  has  drawn  out  the  excess  mercury.  Amalgam  has  also  been 
successfully  used  to  attach  facings  that  have  broken  away  from 
bicuspid  and  molar  bridges.  The  technic  is  as  follows:  The 
porcelain  is  thoroughly  undercut  with  a  carborundum  or  diamond 
disk,  the  gold  is  undercut  with  fissure  and  wheel  burs,  and  the 
soft  mushy  amalgam  is  pressed  on  the  porcelain  facing,  and  the 
facing  is  pressed  into  place.  The  excess  amalgam  is  allowed  to 
squeeze  out  around  the  sides,  and  a  piece  of  sponge  gold  is  plas- 


Fig.  109.  Fig.  no.  Fig.  in.  Fig.  112. 

Figs.  109-112.— Steps  in  the  sponge-gold  process  of  restoring  a  broken-down  root 

with  amalgam  so  that  it  may  readily  be  crowned. 

tared  over  the  outside  of  the  amalgam  and  the  facing,  and  held 
there  until  the  excess  mercury  is  absorbed.  The  patient  can  then 
be  sent  away  with  the  gold  in  position,  care  being  taken  to  see 
that  it  will  not  interfere  with  the  bite.  When  the  patient  returns 
on  the  following  day  the  gold  can  be  polished  off  and  the  amal- 
gam joint  will  be  found  hard  and  firm.  This  method  is  especially 
valuable  in  replacing  facings  for  bicuspids  and  molars  where 
teeth  with  all-porcelain  grinding  surfaces  are  used. 
^  Repair  of  Broken  Roots. — By  using  the  sponge-gold  method 
of  extracting  the  mercury  from  soft  amalgam,  roots  fractured 
beneath  the  gum  can  be  quickly  and  easily  restored  so  as  to 
form  effective  abutments  for  bridges;  or  in  back  teeth  they  can 
be  readily  and  easily  built  up  to  a  complete  masticating  contour. 
The  method  is  as  follows:    Figure  109  represents  a  cross-section 


FILLINGS 


189 


of  a  broken  bicuspid  root  that  has  been  fractured  beneath  the 
gum  margin,  A.  The  irregular  Hnes  represent  the  cavity  pre- 
pared inside  for  the  retention  of  the  amalgam  that  is  to  restore 
the  gum  margin  and  make  the  root  a  suitable,  wholesome  abut- 
ment for  a  crown  or  bridge.  Amalgam  should  be  prepared  as 
previously  described,  then  the  head  of  the  root  and  gum  should 
be  wiped  off  with  4  per  cent,  formalin  or  pure  carbolic  acid, 
and  the  soft  amalgam  inserted  into  the  cavity  of  the  root  and 
tamped  well  into  all  interstices.  Wafering,  as  described,  should 
be  done  until  the  amalgam  has  a  stiff,  doughy  consistency.  There 
should  be  a  final  tamping  and  the  amalgam  should  be  smoothed 
and  shaped  as  in  Fig.  110— B  representing  the  sponge  gold  andC 
the  amalgam.  Then  the  sponge  gold  should  be  pressed  down 
firmly  with  the  thumb,  when  it  will  result  in  a  condition  as  shown 


Fig.  113. 
Figs.  113-117.- 


Fig.  114.  Fig.  115.  Fig.  116.  Fig.  117. 

-Same  principles  can  be  applied  to  the  restoration  of  a  crown  of  a 
tooth. 


in  Fig.  III.  D  represents  the  excess  amalgam  that  extends 
beyond  the  edge  of  the  root,  and  must  be  rem.oved  later.  The 
patient  may  then  be  sent  away,  and  on  the  following  day  the 
restored  root  head  can  be  carved  with  fissure  burs  and  filed  to 
resemble  Fig.  112,  when  a  band  crown  can  be  made  so  as  not 
in  any  way  to  infringe  on  the  gum. 

If  a  complete  amalgam  restoration  of  the  crown  is  desired, 
as  is  sometimes  the  case  in  back  teeth,  the  following  method  can 
be  used:  Figure  113  represents  a  molar  tooth  broken  on  one  side 
beneath  the  gum  line,  as  shown  by  E.  Figure  114  represents  a 
partial  restoration  made  after  the  manner  of  Figs.  109-112. 
This  should  be  made  and  finished  absolutely  free  from  masti- 
cating contact  with  the  occluding  tooth  before  the  occlusal  sur- 
face is  formed.    Then  the  amalgam  and  tooth  should  be  cut  to 


IQO  MODERN  DENTISTRY 

form  a  cup  (Fig.  115)  to  receive  the  second  installment  of 
amalgam  that  should  be  inserted  in  a  soft  condition  and  tamped 
into  position.  The  amalgam  should  be  roughly  molded  to  the 
shape  desired  and  the  occluding  tooth  bitten  into  it  so  as  to 
form  a  perfect  occlusion  (Fig.  116),  It  should  be  carved  to  shape 
so  that  the  swing  of  the  jaws  will  not  disturb  it,  and  it  must  be 
sufficiently  plastic  to  be  molded  without  breaking.  WTien  it  is 
of  the  proper  shape  the  teeth  should  be  closed  and  warmed 
sponge  gold  pressed  firmly  on  the  side,  as  is  shown  in  Fig.  117. 
The  patient  should  wait  some  five  minutes  with  the  Jaws  still. 
After  that  he  may  be  sent  away  with  the  gold  still  adherent; 
if  it  loosens,  it  is  of  Kttle  consequence.  He  should  be  warned 
not  to  bite  on  the  tooth  until  the  following  day,  when  the  filling 
can  be  trimmed  and  carved  as  desired.  The  necessity  for  making 
the  filling  in  two  sections  arises  from  the  fact  that  unless  the 
amalgam  is  supported  during  the  process  of  cry-^tallization  it  is 
easily  broken,  and  therefore  it  is  wise  to  make  the  first  part 
entirely  free  from  any  possibility  of  being  reached  by  the  occlusal 
stress  of  the  opposing  tooth  until  it  has  become  absolutely  hard. 
After  this  has  been  accomplished  the  final  occlusal  surface  can 
be  quickly  and  safely  added. 

The  method  of  making  an  amalgam  filling  with  a  perfect 
contour  against  the  adjacent  tooth,  as  is  shown  in  Fig.  118,  is  easy 
and  simple.  A  represents  the  sound  tooth  and  B  the  tooth 
with  the  cavit}'  to  be  filled.  Care  should  be  taken  to  prepare 
the  ca\-ity  so  that  there  will  be  good  strong  margins  at  the 
cervical  border,  and  also  that  there  will  be  ample  separation 
between  the  decayed  tooth  and  the  one  against  which  the  con- 
toiur  is  to  be  made.  The  dotted  lines  represent  the  diagrammatic 
outline  of  the  ca\dty  within  the  tooth.  After  the  ca\-ity  is  pre- 
pared with  suitable  undercuts,  and  dried  or  flooded  with  an 
antiseptic,  as  may  be  most  feasible,  soft  amalgam  is  pressed 
into  the  ca\'it3'  and  tamped  into  all  the  recesses.  K  there  is  an 
occlusion  with  the  opposing  tooth,  the  teeth  should  be  shut 
upon  the  amalgam  and  the  filling  carved  to  the  desired  shape 
with  a  fine  lancet  or  any  suitable  plastic  instrument.  It  wiU 
then  resemble  the  filling  C  in  Fig.  118.    Then  sponge  gold  can 


FILLINGS 


191 


be  pressed  upon  it,  or  it  can  be  hardened  by  wafering,  so  that  all 
excess  mercury  is  extracted  until  the  filling  becomes  about  as 
hard  as  chalk.  If  the  edges  of  the  tooth  project  slightly  above 
the  filling  after  this  has  been  done,  some  of  the  excess  amalgam 
of  the  filling  can  be  wafered,  rolled,  and  ironed  into  position 
with  a  hot  ball  burnisher.  The  patient  should  be  sent  away, 
with  instructions  not  to  bite  upon  the  fiUing  for  twenty-four 
hours.  When  the  patient  returns,  the  filling  can  be  poHshed 
with  fissure  burs,  sharp  lancets,  or  scrapers,  and,  finally,  by  sand- 
paper disks,  but  care  must  be  taken  not  to  polish  or  cut  away 
the  actual  point  of  contact  between  the  filling  and  the  adjacent 


Fig.  118.— Method  of  building  an  amalgam  con-  Fig.  119.— Method  of  build- 

tour  filling  against  an  adjacent  tooth.  ing  two  contour  amalgam  fill- 

ings against  each  other  without 
aid  of  matrix. 

tooth.  Ordinarily  the  filling  can  be  carved  and  poKshed  without 
separation,  by  careful  carving  up  to  the  contact  point,  for  the 
contact  point  is  polished  by  being  forced  against  the  polished 
enamel  of  the  adjacent  tooth.  Finally,  all  rough  or  sharp  edges 
can  be  eliminated  by  passing  a  fine  band-saw  between  the  filling 
and  the  tooth,  which  will  push  them  apart  and  reduce  all  edges, 
so  that  floss-silk  will  jam  sharply  as  it  is  passed  over  the  contact 
point,  but  will  otherwise  have  free  passage  for  its  daily  duty  of 
cleansing  the  interdental  space. 

If  two  cavities  oppose  each  other,  as  in  Fig.  119,  one  may  be 
built  up  to  the  proper  contour,  as  previously  described,  and 


192  MODERN  DENTISTRY 

polished  at  some  future  sitting,  when  the  second  can  be  inserted, 
or  they  can  both  be  filled  at  once  as  a  common  filling.  The 
wafer  or  sponge  gold  should  be  used  until  the  amalgam  has  be- 
come chalk-Kke,  then  the  two  fillings  can  be  carved  to  have  a 
common  contact  point.  A  fine  steel  band-saw  should  be  passed 
through  the  contact  point  A  and  the  fillings  entirely  separated. 
Then  the  mouth  should  be  rinsed  with  water.  After  this  the 
two  fillings  should  be  ironed  into  absolute  contact  at  the  contact 
point  with  a  hot  ball  burnisher.  They  will  not  join,  as  the  water 
will  act  as  a  bar  against  their  union.  After  this  the  patient  can 
be  dismissed,  and  the  fillings  polished  and  finished  at  the  next 
sitting. 

Gutta-percha  has  been  used  as  a  bond  for  inlays,  crowns,  and 
bridges,  and  therefore,  in  order  to  finish  the  discussion  of  various 
cements  and  also  the  various  filling  materials,  gutta-percha  will 
next  be  considered.  When  used  as  a  cement  for  an  inlay,  a  little 
hard  gutta-percha  should  be  placed  in  the  dried  undercuts  of  the 
cavity  and  spread  with  a  hot  instrument  evenly  over  the  entire 
surface  as  a  lining.  Then  it  should  be  wet,  and  the  inlay,  with- 
out undercuts,  should  be  pressed  upon  it  with  a  hot  instrument 
until  the  gutta-percha  flows  out  of  the  margins  to  a  considerable 
extent.  Then  the  inlay  should  be  removed  and  the  excess  gutta- 
percha should  be  ironed  off  by  the  sharp  edge  of  a  hot  plastic 
instrument,  care  being  taken  to  always  iron  it  toward  the  edge. 
The  inlay  should  be  inserted  a  second  time  and  the  process  re- 
peated until  the  inlay  is  almost  in  position.  Then  it  should  be 
removed  and  the  undercuts  made.  The  surface  of  the  gutta- 
percha should  be  dried  and  the  inlay  inserted  and  sent  horne  with 
a  hot  instrument,  all  excess  gutta-percha  being  removed  with 
a  sharp  knife  and  a  pellet  of  cotton  soaked  in  a  gutta-percha 
solvent,  such  as  oil  of  cajuput,  oil  of  eucalyptus,  or  chloroform. 

This  use  of  gutta-percha,  however,  in  the  light  of  our  present 
cements  is  obsolete,  and  it  is  now  seldom  used  except  for-  temporary 
attachments  or  for  crowns  or  bridges  where  there  is  a  possibihty 
that  they  may  need  to  be  removed  in  case  of  re-infection  due  to 
lack  of  cleanHness  or  to  low  bacterial  resistance.  When  a  crown 
is  to  be  set  in  gutta-percha  the  cavity  in  the  root  should  be 


FILLINGS  193 

beveled  and  kept  moist  so  that  the  gutta-percha  can  be  easily- 
removed  during  the  process  of  fitting.  The  base  of  the  crown 
and  the  pin,  if  it  has  one,  are  then  undercut  and  thoroughly- 
dried.  They  are  then  slightly  moistened  -with  oil  of  cajeput  or 
eucalyptus  and  -white  base-plateg  utta-percha  placed  on  the  pin 
or  within  the  band.  The  crown  is  heated  and  pressed  into  posi- 
tion as  far  as  possible  on  the  root,  which  should  be  wet.  When 
the  gutta-percha  is  cold  the  crown  should  be  removed,  which  is 
easily  accomphshed,  and  the  excess  gutta-percha  trimmed  off 
and  the  process  repeated  until  the  crown  goes  absolutely  into 
position.  Then  it  is  removed,  the  gutta-percha  dried,  the  root 
dried,  shghtly  roughened  and  moistened  with  oil  of  cajeput, 
and  the  crown  heated  and  pressed  into  position.  It  should  be 
held  firmly  in  place  for  a  minute  or  two  and  then  the  patient 
dismissed,  being  told  not  to  bite  upon  it  for  an  hour  or  two. 
After  that  time  it  will  be  firm,  but  at  any  time  heat  from  a  hot 
instrument  appHed  to  the  outside  will  make  its  removal  easy. 
The  same  principle  applies  to  the  insertion  of  bridges  with  gutta- 
percha, although,  as  a  matter  of  fact,  the  author  has  not  used  this 
method  of  retention  oftener  than  once  or  twice  a  year  during 
the  past  ten  years  of  practice. 

Gutta-percha  is  a  most  valuable  filhng  for  cavities  wHere 
decay  is  progressing  rapidly  and  it  is  difficult  to  determine  just 
how  much  can  be  saved  and  just  how  much  should  be  cut  away. 
If  the  tooth  is  soaked  in  carbolic  acid  or  formalin  and  filled  with 
gutta-percha,  at  the  end  of  about  a  month  a  permanent  filhng 
can  be  inserted  with  much  greater  chance  of  success  than  if  the 
temporary  gutta-percha  had  not  been  used.  The  fact  that  the 
temporary  filhng  gives  us  an  opportunity  for  repeated  steriliza- 
tion is,  of  course,  a  great  advantage.  In  addition  to  its  permit- 
ting of  resterilization,  gutta-percha  is  particularly  valuable  as  a 
packing  in  between  teeth  where  the  teeth  are  too  close  together 
and  inflamed  gum  has  worked  into  the  cavity.  In  such  cases 
if  the  gutta-percha  is  inserted  after  a  moderate  excavation  the 
force  of  mastication  will  cause  it  to  spread  the  teeth  and  force 
the  gum  out  of  the  cavity,  so  that  ample  room  can  be  obtained 
for  a  good  interdental  space.  This  separation  ordinarily  takes 
13 


194  MODERN  DENTISTRY 

about  three  months  after  the  filling  has  been  inserted  and  causes 
no  pain. 

Gutta-percha  has  a  wonderful  property  of  becoming  very 
hard  and  adhesive.  It  would  seem  that  a  sort  of  vulcanizing 
takes  place,  making  a  filling  that  at  times  seems  not  unlike 
cement.  The  great  disadvantage  about  gutta-percha  lies  in  the 
fact  that  in  time  it  will  disintegrate  and  discolor.  This  process 
is  very  slow,  but  nevertheless  steady,  and  therefore  the  other 
filling  materials  under  ordinary  circumstances  are  to  be  preferred 
where  durability  is  to  be  desired. 


CHAPTER   VIII 

CHILDREN'S   TEETH 

The  Theory  of  Gum  Lancing  m  Infants.    Care  of  the  Teeth  and 
Gums  After  the  Eruption  of  the  Temporary  Second  Molars. 

Gum  Lancing. — "Teething  is  a  natural  process  and  assistance 
by  lancing  is  unnecessary."  This  is  the  stock  objection  raised 
by  the  opponents  of  this  time-honored  procedure,  but  it  should 
be  remembered  that  the  same  objection  would  hold  with  the 
same  force  against  assisting  nature  with  forceps  during  parturi- 
tion. Many  physicians  maintain  that  retarded  dentition  is 
seldom,  if  ever,  a  cause  of  the  bowel  complaints  and  the  general 
nervous  condition  and  malnutrition  that  are  so  common  among 
children  during  their  first  and  second  summers.  It  is  claimed 
that  lancing  forms  scar-tissue  in  the  gums  that  retards  the  erup- 
tion of  the  teeth.  And  it  is  also  claimed  that  many  a  child  suffer- 
ing from  coHc,  scurvy,  and  a  hundred  and  one  of  the  ordinary 
infantile  ailments  has  been  uselessly  lacerated  with  a  lancet,  and 
the  little  sufferer's  pain,  far  from  being  stiUed,  was  actually 
increased. 

There  is  no  doubt  a  child  suffering  with  incipient  measles, 
smaU-pox,  scarlet  fever,  or  even  a  misplaced  pin  would  not  be 
benefited  by  having  its  gums  lanced,  but  when  the  child  during 
its  dentition  period  suffers  from  malnutrition,  bowel  disorders, 
restlessness  and  fretfulness,  or  shrieks  without  apparent  cause, 
it  is  a  rash  physician  who  would  be  absolutely  sure  that  dentition 
is  not  one  of  the  underlying  causes  of  these  distressing  symptoms, 
even  though  the  gums  may  appear  perfectly  normal.  It  should 
be  remembered  that  the  pain  of  teething  does  not  arise  from  the 
pressure  of  the  tooth  upon  the  gum,  but  that  the  pressure  of  the 
gum  upon  the  tooth  causes  the  pain  by  creating  pressure  upon 
the  underlying  nerve.     A  single  retarded  wisdom  tooth  in  an 

195 


196  MODERN  DENTISTRY 

adult  may  cause  such  pain  and  nervous  shock  that  the  bowels 
will  be  violently  disturbed  and  there  will  be  high  fever,  all  of 
which  symptoms  will  disappear  when  the  entire  grinding  surface 
of  the  offending  molar  is  freed  from  its  overhanging  tooth  capsule. 
The  pressure  of  the  tooth  capsule  on  the  posterior  cusp  alone 
may  cause  these  symptoms,  all  the  other  cusps  being  free. 

The  same  condition  has  been  noted  in  children  of  six  or 
twelve  years  during  the  eruption  of  the  sixth-  and  twelfth-year 
molars.  The  restraint  of  the  posterior  cusp  alone  by  a  tough 
gum  may  in  these  cases  cause  profound  nervous  excitability  with 
its  concomitant  physical  disturbances.  These  disturbances  are 
easily  diagnosed  because  the  patient  is  intelligent  enough  to 
explain.  Therefore,  in  the  case  of  a  screaming,  coKcky,  feverish 
infant  who  cannot  explain,  and  who  possibly  has  not  only  one 
but  eight  teeth  pressing  on  the  dental  pulps,  how  unfair  it  is  to 
the  child  to  ignore  the  fact  that  difficult  dentition  may  be  the 
underl3dng  cause  of  all  the  trouble. 

Since  we  know  that  one  single  cusp  of  an  unerupted  sixth- 
year  molar  often  causes  distressing  systemic  symptoms  that  can 
be  instantly  removed  by  lancing,  the  failure  frequently  encoun- 
tered by  physicians  in  obtaining  relief  after  lancing  is  no  doubt 
often  due  to  imperfect  technic  in  lancing.  Unless  the  dental 
capsule  covering  the  cusps  of  an  erupting  tooth  is  dissected 
absolutely  clear  of  it,  so  as  to  reheve  all  back  pressure  on  the 
nerve  by  the  gum,  lancing  may  cause  no  reHef  whatever.  With 
wisdom  teeth  covered  by  a  large  mass  of  gum  it  is  sometimes  nec- 
essary after  the  gum  has  been  dissected  to  burn  the  capsule 
away  with  trichloracetic  acid.  When  this  is  done,  even  though 
the  gum  still  overlies  the  tooth,  rehef  is  at  once  obtained.  Many 
physicians  fail  to  appreciate  that  the  only  value  in  lancing  Hes 
in  completely  dissecting  the  tooth  free  from  the  dental  capsule. 
The  complete  lancing  of  incisors  and  canines  of  teething  infants, 
to  the  expert,  presents  few  difficulties,  as  the  lancet  can  readily 
be  passed  all  around  the  cutting  edge  of  the  tooth  beneath  the 
gum,  but  in  the  case  of  a  deep-seated  molar  the  overlying  block 
of  gum  must  be  completely  removed  and  the  capsule  absolutely 
cleared  if  the  physician  is  to  be  assured  that  that  particular 


children's  teeth 


197 


tooth  may  not  continue  to  be  a  cause  of  reflex  systemic  disturb- 
ance. And  where,  as  is  often  the  case,  four  molars  may  be  under 
suspicion  at  the  same  time,  and  the  teeth  are  far  under  the  gum, 
it  is  a  nice  question  to  decide  how  much  surgery  is  justified.  It 
has  been  the  author's  experience  that  lancing  of  even  four  molars 
at  a  time  not  only  causes  no  shock  to  the  child  but  results  in 
almost  immediate  rehef.  However,  the  full  history  of  the  child 
must  be  taken  into  consideration,  and  all  infantile  disturbances 
should  not  be  attributed  in  bulk  to  faulty  dentition. 

The  question  of  scar-tissue  formed  by  lancing  has  not  been 
seriously  discussed,  as  ordinarily  the  tooth  erupts  long  before 
scar- tissue  sufficiently  dense  to  interfere  can  be  formed;  and  if 
scar-tissue  does  form  the  great  rehef  obtained  by  judicious 
lancing  more  than  compensates  for  the  possible  necessity  of  a 
second  or  even  a  third  lancing. 

Care  of  Children's  Teeth  and  Gums. — Unless  the  child  has 
been  very  badly  nourished  during  gestation,  or  within  the  first 
few  years  of  childhood  suffers  either  from  malnutrition  or  some 
disease  such  as  measles  or  scarlet  fever,  the  first  and  even  the 
second  teeth,  the  wisdom  teeth  excepted,  are  likely  to  erupt 
sound  and  normal.  The  formation  period  of  the  enamel  of  all  but 
the  wisdom  teeth  Hes  within  these  few  years,  and  if  the  enamel 
is  well  formed  prior  to  its  emergence  from  the  gum,  the  tooth 
will  have  every  opportunity  for  perfect  development  as  the  roots 
and  dentin  go  on  forming  after  it  is  erupted.  But  with  the  enamel 
this  is  not  so,  for  when  the  tooth  emerges  from  the  gum  the  enamel 
organ  dies  and  no  more  enamel  can  be  formed.  The  formed 
enamel  can  harden  or  soften  according  to  its  nature,  as  shown 
in  Chapter  III,  but  with  the  emergence  of  the  tooth  from  the  gum 
growth  in  the  enamel  ceases  forever.  The  enamel  first  forms 
at  the  tips  of  the  cusps  or  cutting  surfaces  of  the  teeth,  as  in 
Fig.  120,  the  formed  enamel  being  shown  by  the  shaded  portion, 
and  it  frequently  happens  that  the  permanent  molars  erupt 
before  the  pits  or  fissures  in  the  grinding  surfaces  are  completely 
closed,  thus  destroying  the  enamel  organ  before  its  work  is  com- 
pleted. Sometimes  although  the  bottom  of  the  pits  or  fissures 
are  covered  with  sohd  enamel,  the  fissure  itself  is  partly  filled 


198  MODERN  DENTISTRY 

with  a  soft  material  that  acts  as  a  special  lodgment  for  infection. 
Therefore,  the  first  thing  a  dentist  should  do  when  a  child  is 
brought  to  him  is  to  carefully  examine  all  the  pits  and  fissures 
with  a  fine,  sharp  piano-wire  explorer.  The  wire  is  not  hard 
enough  to  penetrate  into  normal  enamel,  and  so,  when  jammed 
into  each  suspected  place,  if  it  sticks  on  being  withdrawn,  the 
dentist  can  be  assured  that  there  is  a  soft  spot  which  should  be 
poHshed  out  with  a  stone  or  bur  until  the  explorer  no  longer 
sticks.  Normal  mastication  of  food  will  keep  the  bottom  polished 
and  will  absolutely  prevent  decay.  The  fissure  must  be  made 
self-cleansing,  and  if  the  enamel  is  penetrated  entirely  the  softened 
structure  must  be  entirely  removed  and  a  cement  fiUing  inserted. 
This  procedure  will  not  weary  the  child  and  will  enable  the  tooth 
to  safely  mature,  when  it  can  be  filled  in  a  more  permanent  man- 
ner.   In  any  case  it  is  not  a  bad  procedure  to  flow  a  thin  layer  of 


Fig.  120. — Showing  diagrammatically  formation  of  enamel  at  upper  surface  of  the 
dental  capsule,  the  white  portion  being  yet  soft  and  gelatinous. 

phosphate  of  zinc  cement  into  the  grooves  after  the  polishing 
is  completed.  This  makes  the  tooth  smooth  to  the  action  of 
the  tongue  and  gives  an  excellent  opportunity  for  the  cut  enamel 
to  gradually  harden  as  the  cement  dissolves.  I  speak  of  the 
enamel  hardening,  for  the  results  of  my  experiments,  as  given 
in  Chapter  III,  indicate  that  enamel  is  harder  on  the  surface 
than  underneath,  and  when  it  is  cut  the  exposed  surface  becomes 
hard  also — a  sort  of  case-hardening  process  that  renders  it 
resistant  to  attrition  and  yet  not  Hable  to  fracture.  At  least, 
whatever  the  explanation  may  be,  the  above-mentioned  pro- 
cedure gives  excellent  results,  and  when  the  cement  is  worn  or 
washed  away  by  the  saliva  the  tooth  performs  its  functions 
satisfactorily  without  further  filling. 


children's  teeth 


199 


If  this  has  been  done  carefully  as  soon  as  the  teeth  erupted 
and  the  teeth  are  not  deformed,  and  if  floss-silk  and  tooth-brush 
are  used  as  described  in  Chapter  II,  the  teeth  and  gums  should 


I 


II 


I 


u 


! 


J 


Fig.  121. — Carborundum  stones  used  for  polishing  grooves  and  softened  enamel 

in  children's  teeth. 


always  be  free  from  decay  and  infection.  But,  as  a  matter  of  fact. 
the  floss-silk  and  tooth-brush  will  seldom  be  used  as  recommended. 
Parents  should  not  only  tell  the  children  to  brush  the  teeth  and 
to  use  floss-silk,  but  should  see  that  the  children  do  it  properly. 


200  MODERN   DENTISTRY 

Otherwise  the  bacteria  will  collect  against  the  enamel  and  remain 
undisturbed  indefinitely,  and  finally  cavities  of  decay  will  appear 
in  the  temporary  teeth.    When  the  spots  of  decay  are  small  and 
have  not  infected  the  pulps  they  can  be  made  comparatively 
harmless,  since  they  can  be  cut  out  and  filled  with  amalgam, 
gutta-percha,  or  cement.     Then  if  the  parents  take  heed,  and 
see  that  the  teeth  are  properly  cleansed  with  floss-silk  and  tooth- 
brush, the  child  may  grow  to  maturity  and  have  a  perfectly 
healthy  set  of  teeth.    But  if  a  pulp  in  a  temporary  tooth  becomes 
infected  so  that  the  pulp  has  to  be  removed,  we  are  face  to  face 
with  one  of  the  most  serious  and  difficult  problems  in  dentistry. 
And  the  worst  part  of  the  whole  miserable  dilemma  lies  in  the 
fact  that  it  is  so  easily  preventable  by  proper  cleansing.    Any 
mother  who  brushes  a  child's  teeth  properly  and  uses  floss-silk 
carefully  three  minutes  a  day  is  giving  the  child  years  of  health 
and  vigorous  maturity.    The  only  proviso  is  that  she  must  do  it, 
or  see  that  it  is  done,  every  day,  not  every  other  day  or  once  a 
week.     Nor  does  it  assist  matters  when  decay  has  penetrated 
to  the  pulp  to  hear  her  exclaim,  "Well,  I  told  him  to  brush  his 
teeth!"     To  think  that  the  poor  dentist  has  to  listen  to  such 
drivel  day  in  and  day  out!    Tell  a  child  of  seven,  eight,  or  ten 
to  brush  his  teeth!     A  child  of  eight  or  ten  does  not  wish  to 
brush  his  teeth,  does  not  know  how,  and  won't  do  it  even  if  he  is 
taught,  unless  he  is  coaxed  and  made  to  do  it ;  and  yet  it  is  ordi- 
narily during  these  years  that  the  enamel  becomes  permanently 
infected  and  the  foundation  for  firmly  intrenched  mouth  in- 
fection is  laid.     The  fundamental  cause  of  mouth  infection  is, 
first,  ignorance  on  the  part  of  the  parents,  and  after  that  laziness 
or  overwork;  for  it  is  quite  conceivable  that  a  mother  of  six 
young  children  may  readily  prefer  to  send  the  children  to  the 
dentist  twice  a  year,  and  put  the  responsibility  on  him,  than  to 
go  through  with  the  great  ordeal  of  seeing  that  over  one  hundred 
teeth  are  carefully  flossed  and  brushed  each  day.     And  yet  if 
she  really  knew  the  good  she  would  do  them  and  the  money 
she  would  save,  I  am  sure  the  ordinary  mother  would  gladly 
see  that  her  children's  teeth  were  kept  clean. 

However,  let  us  suppose  the  evil  is  done,  and  the  child  is 


children's   teeth  20I 

brought  to  us,  when  seven  or  eight  years  old,  with  cavities  in  the 
temporary  teeth  that  have  extended  until  the  pulp  is  exposed, 
and  well-defined  spots  of  decay  have  started  in  the  sixth-year 
molars  and  the  central  incisors.  The  child's  gums  are  usually 
inflamed  and  the  teeth  coated  with  white  masses  of  bacterial 
deposits.  The  first  essential  is  to  gain  the  confidence  of  the 
child.  It  is  well  to  merely  cleanse  the  child's  teeth  at  the  first 
visit,  and  show  him  how  to  use  the  tooth-brush.  The  tooth- 
brush should  be  small  and  of  the  size  and  design  shown  in  Fig.  9, 
and,  above  all,  should  be  dipped  in  hot  water  and  allowed  to 
cool  prior  to  its  first  use  on  the  sensitive  gums.  This  will  prevent 
too  great  irritation  and  will  not  discourage  the  child  from  coming 
again.  The  movements  to  be  used  in  brushing  the  teeth  are 
given  in  Chapter  II.  The  child  should  also  be  taught  to  use 
floss-silk,  as  previously  stated,  in  order  that  the  bacterial  masses 
may  be  removed  from  between  the  teeth  once  at  least,  if  not 
twice,  daily.  The  silk  should  be  held  in  the  manner  described 
in  Chapter  II.  This  is  most  important.  The  taut  part  should 
be  pressed  down  between  the  tooth  surfaces  of  each  interdental 
space,  sweeping  one  side  going  in,  traversing  firmly  across  the 
gum,  and  then  sweeping  the  side  of  the  adjacent  tooth  going  out. 
This  is  not  a  simple  operation;  it  requires  instruction  and  patience 
if  it  is  to  be  mastered,  and  nothing  but  careful  training  on  the 
part  of  the  dentist  and  parents  will  make  the  child  have  either 
the  knowledge  or  the  will  to  do  it  properly.  The  next  thing  is 
to  remove  the  green  stain  that  is  usually  found  on  the  teeth  by 
first  flowing  a  little  tincture  of  iodin  on  them  and  then  polishing 
with  brush  and  pumice.  Never,  if  it  can  possibly  be  avoided, 
should  a  child  be  hurt  on  his  first  visit,  and  at  no  time  should  a 
child  be  taxed  beyond  the  easy  Kmit  of  his  endurance.  Of  course, 
if  a  child  comes  to  a  dentist  with  an  abscessed  tooth,  the  open- 
ing of  it  may  hurt,  but  no  more  pain  should  be  inflicted  than  is 
absolutely  necessary  to  give  relief.  On  the  second  visit  a  small 
cavity  of  decay  may  be  fiUed.  This  should  be  accomplished 
by  carefully  yet  rapidly  cutting  out  the  decay  with  a  swift 
sweep  of  a  rapidly  revolving  sharp  bur.  It  should  never  take  over 
a  few  seconds  to  accompHsh  this,  and  if  the  child  is  permitted 


202  MODERN  DENTISTRY 

to  hold  the  napkin  around  the  tooth  with  his  fingers  while  the 
work  is  being  done,  it  is  astonishing  how  readily  and  even  cheer- 
fully he  will  bear  the  necessary  pain.  The  mere  fact  that  the 
child  is  assisting  by  holding  the  napkin  distracts  his  attention. 
It  is  astonishing  how  quickly  a  child  responds  to  the  S3rmpathy 
of  the  dentist  who  really  loves  children  and  desires  to  assist  them. 
Those  who  are  not  capable  of  feeling  this  sympathy  laugh  and 
scoff  at  such  a  claim,  but  it  has  been  my  experience  that  children 
treated  lovingly  and  honestly,  skilfully  and  quickly,  are  the  best 
patients  a  dentist  can  have,  and  when  their  confidence  is  gained 
they  will  bear  with  fortitude  pain  that  would  make  an  older 
person  wince.  The  main  essentials  in  dealing  with  children  is 
never  to  deceive  them,  never  to  overtax  their  power  of  resistance, 
and  never  to  fail  to  let  them  see  that  you  care  for  them  person- 
ally, but  with  it  all  to  make  them  feel  that  they  must  obey. 
If  a  thing  has  to  be  done,  persuade  and  coax  the  child  if  neces- 
sary, but  see  that  it  is  done  before  he  leaves  the  chair.  And  it 
will  be  a  great  proof  of  a  dentist's  discretion  to  plan  for  any  one 
visit  an  efficient  course  of  procedure  that  will  not  overtax  the 
child's  power  of  endurance. 

When  the  cavity  of  decay  in  a  temporary  tooth  has  been 
excavated,  the  tooth  should  be  filled  so  that  it  will  last  four  or 
five  years,  or  until  it  comes  out  to  make  room  for  its  successor. 
In  such  a  case  the  putting  on  of  rubber-dam  or  jamming  the  gum 
with  clamps  is  folly.  The  amalgam,  cement,  or  gutta-percha 
should  be  prepared  for  use  according  to  the  material  to  be  used, 
and  then  the  napkin  should  be  applied  and  the  child  told  to 
hold  it  in  position.  Then  the  cavity  should  be  quickly  wiped 
out  with  a  pellet  of  cotton  moistened  with  carbolic  acid  or  nitrate 
of  silver,  and  the  filHng  at  once  inserted.  If  amalgam  is  used 
the  antiseptic  will  do  good,  and  if  the  cement  or  gutta-percha 
are  deemed  desirable  the  small  amount  of  moisture  due  to  the 
antiseptic  film  will  be  only  a  theoretic  objection,  especially 
if  the  cavity  contains  judicious  undercuts.  The  same  procedure 
applies  to  filling  the  permanent  teeth  of  a  child.  Gutta-percha 
and  cements  can  certainly  tide  the  child  over  the  formative 
period  of  the  dental  roots  and  pulps,  and  then  operations  of 


CHILDREN  S   TEETH  203 

greater  length,  if  necessary,  can  be  performed.  It  will  be  noted 
that  this  gentleness  and  firmness  applies  to  mature  patients 
as  well  as  children,  but  it  is  especially  essential  in  the  control  of 
children.  A  doctor  who  is  not  a  thorough  humanitarian  has  no 
right  to  call  himself  a  doctor.  A  doctor  was  once  talking  to  a 
bright  woman  about  the  doctor's  Hfe,  and  after  the  late  hours, 
loss  of  sleep,  and  constant  worry  had  been  gone  over,  the  woman 
said,  "Well,  medicine  is  certainly  a  very  poor  business."  "Quite 
true,  madam,"  was  the  response,  "but  it  is  a  very  fine  profession." 
And  so  the  dentist  who  perpetrates  mechanical  operations  of 
unnecessarily  tedious  length  is  not  a  surgeon,  but  a  mechanic, 
and  should  confine  his  efforts  to  the  workbench,  not  to  the 
sensitive  human  tissues. 

Exposed  Pulp  in  Temporary  Teeth.— When  the  dentist 
finds  a  temporary  tooth,  usually  one  of  the  molars,  with  a  cavity 
that  has  involved  the  pulp  he  is  confronted  with  a  problem  that 
will  tax  his  ability  to  its  utmost.  It  is  difiicult  to  treat  and  fill 
the  canals  of  a  permanent  molar,  but  with  the  temporary  molar 
the  canals  not  only  have  to  be  treated  and  filled,  but  they  have 
to  be  filled  with  a  root  filhng  that  will  absorb  as  the  roots 
absorb,  when  the  permanent  tooth  beneath  begins  to  emerge 
to  take  its  place.  If  the  pulp  is  alive  it  should  be  anesthetized 
by  means  of  the  novocain  pressure  method,  as  described  in 
Chapter  VI,  and  should  then  be  thoroughly  removed  from  the 
canals  by  Beutelrock  drills  and  the  piano-wire  broaches.  Then 
Buckley's  mixture  of  formafin  and  tricresol  should  be  sealed  in 
with  cement  and  the  Httle  patient  dismissed.  It  is  wise  to  wait 
a  fuU  month  in  order  to  be  sure  that  the  irritation  of  the  root 
tips  has  entirely  subsided.  When  the  patient  returns  the  napkin 
or  cotton  roll  can  be  applied  either  with  the  clamp  or  held  by 
the  child,  and  the  filling  and  dressing  removed  by  a  swiftly 
revolving  drill.  The  same  treatment  should  again  be  repeated, 
and  within  a  week  the  root  canals  should  be  permanently  filled 
in  the  following  manner:  The  filhng  and  dressing  should  be 
removed  as  before,  hot  air  should  be  appHed,  and  the  canals 
quickly  dried.  Then  a  paste  of  oil  of  cloves  and  oxid  of  zinc 
should  be  flowed  and  Hghtly  tamped  into  the  canals.    Any  excess 


204  MODERN  DENTISTRY 

oil  of  cloves  should  be  absorbed  by  a  suitable  amount  of  oxid 
of  zinc  added  to  the  pulp  chamber.  All  excess  can  be  wiped  or 
scraped  from  the  pulp  chamber,  and  the  tooth  can  be  filled 
with  any  suitable  material,  such  as  amalgam,  cement,  or  gutta- 
percha. Of  course,  chloro-percha  and  gutta-percha  can  be  used 
in  the  root  canal,  but  the  oil  of  cloves  seems  to  give  the  best  results 
and  has  the  property  of  being  absorbed  with  the  rest  of  the  root 
as  the  permanent  tooth  underneath  erupts.  The  best  way, 
however,  is  to  prevent  the  decay  of  the  tooth  before  it  starts 
by  seeing  that  its  entire  surface  is  kept  clean  with  floss-silk  and 
the  tooth-brush. 

Fractured  Teeth. — One  of  the  most  distressing  accidents 
that  can  happen  to  children's  teeth  is  the  fracture  of  a  newly 
erupted  permanent  tooth  that  exposes  the  pulp  long  before  it 
has  completed  its  task  of  forming  the  tip  of  the  root.  It  is  almost 
invariably  one  or  both  of  the  upper  central  incisors  that  is  frac- 
tured. Sometimes  the  fracture  is  almost  enough  to  expose  the 
pulp,  but  not  quite.  The  pink  of  the  pulp  vessels  may  be  just 
visible  through  the  fractured  surface,  and  yet  the  pulp  may  not 
be  exposed.  Under  such  conditions  the  fractured  surface  should 
be  wiped  off  with  pure  carbolic  acid,  thoroughly  dried,  and  a  film 
of  thin  cement  flowed  over  it  and  allowed  to  harden.  This  may 
protect  the  pulp  so  that  it  will  continue  its  life  for  three  or  four 
years  or  until  the  root  is  fully  formed,  when  the  tooth  can  be 
restored  to  its  normal  color  and  contour  by  a  skilfully  appHed 
porcelain  filling.  In  the  meantime,  if  desired,  the  tooth  may  be 
temporarily  restored  with  cement.  But  when  the  pulp  is  exposed 
so  that  its  death  is  imperative,  it  is  wise  to  apply  novocain  and 
remove  the  pulp  at  once.  When  this  has  been  accomplished 
and  the  soft  parts  have  been  thoroughly  removed,  it  is  frequently 
found  that  the  entire  tooth  is  composed  of  little  more  than  enamel 
and  cementum,  the  dentin  being  almost  entirely  missing.  The 
pulp  chamber  instead  of  being  minute,  as  it  would  have  been  if 
the  tooth  had  matured,  is  a  large  canal  with  its  diameter  varying 
from  0.125  iiich  at  the  fractured  edge  to  0.0625  inch  at  the  root  tip. 
And  what  is  of  more  serious  consequence,  the  tip  of  the  root  is 
so  imperfectly  developed  and  so  full  of  organic  material  that  in 


children's  teeth  205 

the  course  of  time  it  is  sure  to  be  partly  absorbed,  and  therefore 
if  it  is  thoroughly  filled  to  the  end,  such  absorption  will  leave 
a  projecting  root-canal  filling.  On  the  other  hand,  if  the  foramen 
is  not  filled  to  the  end  the  force  of  mastication  will  drive  the 
sharp  edges  of  the  partly  formed  apical  foramen  into  the  tissues, 
making  an  irritation  that  is  almost  certain  to  cause  an  infection 
which  will  result  in  a  chronic  alveolar  abscess.  Under  such  con- 
ditions the  tooth  and  root  should  be  carefully  studied  with  the 
a;-ray,  a  hard  tube  being  used  for  the  differentiation  of  the  hard 
calcic  portions  of  the  tooth  and  a  soft  tube  being  used  to  bring 
out  the  soft  tissues,  as  represented  by  inflammatory  or  alveolar 
degeneration.  This  will  be  of  incalculable  value  in  determining 
the  depth  of  the  root-canal  filHng. 
The  pulp  chamber  should  be  thor- 
oughly sterilized  with  applications 
of  pure  carbohc  acid,  followed  by  a 
4  per  cent,  aqueous  formaldehyd 
solution,  which  should  be  sealed  in 
with  phosphate  cement.  If  an  ab- 
scess has  formed  at  the  tip  it  is  ad- 
visable to  squeeze  into  it  a  drop 
or    two    of    pure    carbolic    acid    by     .     ^'^-    12 2. -Diagrammatic 

-,„  ,  1    r   11  11  1  illustration  of  a  child's  broken 

filhng  the  canal  full  and   then  mak-     ^^^^^^^  ^^-^^^  ^^^-^^  ^^^  ^d- 
ing   pressure  on  the  external  open-     jacent  teeth. 
ing  with  a  ball  of  soft,  unvulcanized 

rubber.  After  this  has  been  accomplished  a  cotton  dressing 
should  be  inserted  and  the  tooth  sealed  up  with  cement  for  about 
a  week.  When  the  child  returns,  careful  measurements  of  the 
root  outline  should  be  made  on  the  a--ray  plate,  and  these  should 
be  compared  with  similar  measurements  made  on  the  tooth, 
so  that  the  exact  size  and  length  of  the  pulp  canal  from  the  broken 
edge  to  the  apical  foramen  can  be  ascertained.  Then  the  upper 
part  of  the  canal  should  be  filled  with  a  plug  of  gutta-percha, 
care  being  taken  that  it  accurately  fits  the  apical  foramen. 
This  is  a  very  nice  procedure,  as  is  shown  by  the  illustration 
(Fig.  122).  A  represents  the  broken  tooth;  B  and  C,  the  normal 
adjacent  teeth.    The  dotted  lines  show  the  outline  of  the  pulp 


2o6  MODERN  DENTISTRY 

chamber  and  apical  foramen.    D  represents  the  area  of  softened 
inflamed  tissue  at  the  end  of  root.    E  represents  the  uncalcified 
portions  of  the  normal  tips  of  the  adjacent  teeth.     The  black 
area,  F,  represents  the  position  the  gutta-percha  should  take. 
If  a  small  short  cone  of  gutta-percha  is  thrust  into  the  canal 
on  the  end  of  a  probe  it  will  go  completely  through  the  tip  into 
the  tissues,  making  an  added  source  of  irritation,  and  if  a  large 
bulky  piece  of  gutta-percha  is  jammed  into  the  canal  the  chances 
are  that  it  will  not  reach  the  foramen  at  all.    The  only  practical 
way  out  of  such  a  dilemma  is  to  see  that  the  root  canal  is  abso- 
lutely conical  to  the  tip.    This  can  be  accomplished  by  a  suitable 
reamer.    Then,  while  the  canal  is  allowed  to  remain  wet  with 
a  2  per  cent,  formaldehyd  solution,  a  piece  of  gutta-percha  is 
molded  into   a   cone    approximately   the    correct  size,   heated 
slightly,  and  pushed  with  a  large  probe  as  far  into  the  canal  as  it 
will  go.    It  should  then  be  allowed  to  cool.    Then  it  should  be 
withdrawn  on  the  end  of  the  probe,  sHghtly  heated  again,  and 
pushed  in  again  and  once  more  allowed  to  cool.    So  long  as  the 
canal  is  wet  the  removal  of  the  cone  will  be  easy.    This  should 
be  tried  again  and  again  until  the  measurements  show  that 
the  solid  cone  of  gutta-percha  has  passed  the  end  of  the  conical 
root  canal  and  has  sealed  it  perfectly.    Then  the  cone  should  be 
once  more  withdrav^n,  a  scratch  having  been  first  made  on  the 
probe  opposite  th.       'oken  edge  of  the  tooth.     Then  a  careful 
measurement  of  the  exact  distance  of  the  foramen  from  the  broken 
edge  of  the  tooth  should  be  made  with  another  probe  having  a 
hooked  tip.     The  depth  should  be  compared  with  that  of  the 
x-xdiy  plate  and  the  exact  distance  should  be  marked  off  on  the 
gutta-percha  from  the  scratch  on  the  probe  and  the  excess  gutta- 
percha cut  off.    When  that  has  been  done  the  cone  on  the  probe 
should  be  allowed  to  cool  and  the  root  canal  thoroughly  dried 
with  hot  air  and  moistened  with  oil  of  eucalyptus  on  a  shred  of 
cotton.     Then  the  gutta-percha  cone  and  the  probe  should  be 
inserted  into  the  tooth  firmly  up  to  the  mark  on  the  probe,  which 
ought  to  bring  the  gutta-percha  exactly  to  the  end  of  the  root 
canal.    The  gutta-percha  probe  can  then  be  left  in  position  for 
a  minute  or  two  in  order  that  the  oil  of  eucalyptus  may  make  a 


CHILDREN  S   TEETH  207 

firm  union  between  the  gutta-percha  and  the  tooth.  Then  a  hot 
instrument  should  be  placed  against  the  probe  within  the  tooth 
cavity.  This  will  heat  the  metal  so  that  it  can  readily  be  with- 
drawn, leaving  the  gutta-percha  cone  in  position.  After  the 
probe  has  been  withdrawn  the  hole  in  the  gutta-percha  can 
be  filled  up  by  tamping  the  gutta-percha  into  position  with  a  hot 
instrument,  leaving  the  tip  of  the  root  evenly  sealed.  On  the 
following  day  another  oj-ray  can  be  taken,  and  if  the  gutta-percha 
is  not  absolutely  in  position  it  can  be  pushed  a  little  further  with 
hot  instruments,  for  it  is  better  that  it  should  extend  from  the 
orifice  very  slightly  than  to  allow  the  undeveloped  foramen  to  be 
unfilled.  The  tooth  can  then  be  bleached  as  described  in  Chap- 
ter VI,  and  a  porcelain  tip  made  to  restore  the  tooth  to  its  normal 
length. 

The  ideal  surgical  treatment  of  the  tip,  of  course,  would  be  to 
go  through  the  alveolar  process  with  a  bone  drill  and  amputate  the 
end  of  the  root,  leaving  the  gutta-percha  smooth  and  even; 
but  at  the  age  of  seven,  eight,  or  nine  the  mouth  is  too  full  of  the 
underl)dng  permanent  teeth,  and  the  jaw-bone  is  too  small  in 
its  development  to  safely  attempt  such  a  procedure.  It  is  better 
to  coax  such  a  broken  tooth  along,  soothing  any  inflammatory 
outbreaks  with  iodin  and  other  quieting  treatment  until  the 
jaw  is  more  fully  developed.  Then  at  the  age  of  fourteen,  if  the 
tip  is  not  in  a  healthy  condition,  root  ampu  "  jn  with  novocain 
can  be  undertaken  with  every  possibility  of  permanent  good 
results. 

ORTHODONTIA    FOR    THE    GENERAL    PRACTITIONER    OF    DEN- 
TISTRY 

The  straightening  of  children's  teeth  has  undergone  a  great 
revolution  during  the  last  twenty  years,  and  has  developed 
from  a  haphazard,  hit-or-miss  procedure,  that  frequently  resulted 
in  more  harm  than  good,  into  a  precise  science  that  produces 
permanent  results.  And  strange  to  say,  the  originator  of  the 
fundamental  principles  underlying  the  modern  method  was  a 
Frenchman  who  lived  some  two  hundred  years  ago — Pierre 
Fauchard,  the  father  of  professionaHsm  in  dentistry.    He  scorned 


2o8  MODERN  DENTISTRY 

that  human  suffering  should  be  made  a  field  for  selfish  commercial 
exploitation,  and  therefore  freely  told  of  his  discoveries  to  all 
who  would  listen,  when  each  fellow-worker  was  guarding  his 
secret  as  personal  property.  Among  Pierre  Fauchard's  many 
discoveries  was  the  expansion  arch  which  is  now  generally 
accepted  as  the  best  means  of  straightening  crooked  teeth.  His 
plan  was  to  attach  to  the  teeth  an  arch  of  spring  wire  of  the 
shape  that  the  human  arch  ought  to  assume,  and  then,  by  liga- 
tures, to  draw  the  teeth  into  position  and  hold  them  there,  letting 
the  arch  act  also  as  a  retention  appliance.  But,  like  most  great 
ideas,  his  plan  was  too  simple  and  direct  to  be  understood  or 
accepted.  After  his  death  the  expansion  arch  was  neglected 
and  forgotten.  Later,  practitioners  in  straightening  one  tooth 
frequently  made  another  crooked  with  appliances  of  great 
complexity  and  size.  These  appliances  frequently  injured  the 
gums  and  teeth  permanently  because  it  was  impossible  to  keep 
them  clean.  Moreover,  the  later  dentists  almost  invariably 
started  to  straighten  by  casually  extracting  a  few,  which  made 
facial  distortions  and  malocclusions  that  were  ten  times  worse 
than  if  the  patient  had  never  seen  a  dentist. 

But  about  twenty  years  ago  Angle,  of  St.  Louis,  Baker,  of 
Boston,  and  Case,  of  Chicago,  all  awoke  to  the  advantages  of  the 
expansion  arch,  and  it  was  shortly  afterward  that  the  Angle 
School  of  Orthodontia  was  started.  Angle  made  appliances 
that  were  of  almost  universal  application,  and  he  classified  the 
various  procedures,  by  which  crooked  teeth  could  be  straightened 
with  quickness  and  precision.  A  conscientious  old  dentist  of 
the  old  school  once  said  at  a  dental  meeting  that  he  had  been 
paid  thousands  of  dollars  for  straightening  children's  teeth,  and 
he  regretted  to  say  that  the  teeth  had  never  remained  straight, 
and  that  untold  harm  had  resulted  from  the  regulating  appliances, 
and  therefore  the  money  paid  had  been  more  than  wasted. 
Naturally,  he  was  opposed  to  straightening  teeth.  And  in  the 
light  of  the  work  he  had  done  this  old  gentleman  was  quite 
correct.  But  the  work  started  by  Fauchard  and  carried  on  by 
Angle  was  a  work  that  converted  chaos  into  order,  hideousness 
and  disease  into  beauty  and  health.    The  principles  laid  down  by 


CHILDREN  S   TEETH  209 

Angle  and  his  co-workers  were  that  the  teeth  were  created  by 
a  better  intelligence  than  theirs,  and  if  there  were  thirty-two 
permanent  teeth  it  was  better  to  utilize  all  of  them  and  learn 
their  design  and  proper  relation  than  to  extract  some  teeth  and 
then  plan  what  should  be  done  with  the  rest.  Angle  formulated 
the  theory  that  the  teeth  did  not  grow  to  fit  the  face,  but  the 
face  grew  to  fit  the  teeth.  It  was  discovered  that  if  the  teeth 
could  be  made  to  assume  their  true,  normal  arch  the  rest  of  the 
face  would  develop  to  corresponding  symmetry  and  beauty. 
Also  that  the  arch  of  the  teeth  was  the  keystone  on  which  the  de- 
velopment of  the  upper  bones  of  the  face  and  forehead  depended. 
If  the  arch  was  constricted,  the  openings  in  the  nose  were  les- 
sened or  even  closed,  preventing  proper  breathing.  The  passage 
of  the  air  through  the  nose  being  cut  off,  air  pressure  was  not 
exerted  in  the  various  sinuses  of  the  face,  and  therefore  this 
important  stimulant  to  facial  development  was  weakened  or 
entirely  missing.  And  so  the  new  school  of  orthodontia  started 
out  with  the  endeavor  to  understand  nature's  plan  and  to  co- 
operate with  it. 

Thirty  years  ago  it  was  the  invariable  rule  never  to  start  to 
straighten  teeth  until  the  permanent  canines  had  fully  erupted. 
Now,  in  the  light  of  Angle's  work,  every  dentist  knows  or  ought 
to  know  that  when  the  canines  have  emerged  from  the  gum  it  is 
almost  too  late  to  do  effective  work.  At  least  it  will  take  four 
or  five  times  the  amount  of  work  and  consequent  pain  and  suffer- 
ing, to  accomplish  a  harmonious  result,  that  it  would  have  taken 
if  the  teeth  had  been  placed  in  their  true  positions  before  the 
canines  erupted.  This  is  so  because  the  canines  are  now  known 
to  lock  the  arches  into  their  permanent  positions.  Formerly, 
the  dentist  pulled  and  yanked  the  teeth  hither  and  yon  in  a  vain 
hope  that  with  the  help  of  Providence  and  a  little  luck  they 
would  come  straight.  The  aim  of  even  the  most  advanced 
practitioners  was  to  get  the  teeth  of  a  child  into  the  position 
they  should  assume  in  an  adult,  and  to  hold  them  rigidly  in  place 
imtU  the  child  grew  up.  Thus  all  expansion  and  development 
of  the  facial  bones  was  hampered,  and  it  is  not  surprising  that 
they  began  to  revert  to  their  former  irregularity  as  soon  as  the 
14 


2IO  MODERN  DENTISTRY 

appliances  were  removed.  The  great  advance  made  by  Angle 
and  his  followers  lay  in  the  fundamental  idea  that  the  teeth 
should  be  made  to  develop  along  normal  Hnes,  and  in  the  for- 
mulation of  a  fundamental  law  that  governed  such  development. 
Nature's  shifting  of  the  permanent  teeth  into  the  positions 
of  the  temporary  teeth  during  the  development  of  a  child  is  a 
stupendous  engineering  feat  not  surpassed  by  that  of  a  railroad 
that  changes  all  its  tracks  and  grades  without  interrupting 
traffic.  The  wonder  hes  not  in  the  fact  that  the  second  teeth 
should  occasionally  come  in  crooked  when  they  replace  the  first 
teeth,  but  that  they  would  ever  be  able  to  replace  them  at  all 
with  perfect  occluding  arches.  When  it  is  appreciated  that 
before  the  child  is  seven  years  old,  all  of  the  full-sized  crowns 
of  the  permanent  teeth,  the  wisdom  teeth  excepted,  are  packed 
away  in  the  small  face,  and  that  without  disturbing  mastication 
or  nutrition  the  roots  of  the  first  teeth  must  be  absorbed,  and 
the  replacing  large  second  teeth  must  emerge  into  graceful  lines 
from  their  crowded  position  as  the  face  develops,  the  wonder  of 
it  is  beyond  comprehension.  Such  a  magnificent  engineering 
feat  is  worthy  of  the  Master  Mind. 

Having  grasped  the  idea  that  the  process  of  dentition  is  the 
result  of  a  wonderful  engineering  plan,  it  can  then  be  appreciated 
that  a  Httle  hardening  of  the  bone  by  inflammation,  or  a  little 
extra  resistance  of  the  capsule  ui  eruption,  or  a  httle  retardation 
of  bone  development  by  lack  of  nutrition  or  disease  may  readily 
result  in  producing  discord.  Therefore,  it  is  not  for  the  dentist 
to  attempt  to  pull  or  push  the  teeth  into  adult  position,  but  merely 
to  assist  the  great  plan  of  nature  when  accident  is  obviously 
retarding  or  defeating  it.  A  tooth  pulled  or  wrenched  from  its 
fully  developed  socket  into  a  new  position  in  the  bone  will  ob- 
viously tend  to  return  to  that  socket;  but  if  durmg  the  formative 
stage  of  the  alveolar  process,  before  the  permanent  socket  is 
estabHshed,  the  tooth  is  guided  into  the  normal  position,  the 
natural  process  of  development  and  the  focusing  of  the  normal 
forces  of  mastication  will  obviously  keep  it  in  position.  The 
dentist  must  not  fight  against  nature's  plan  and  supplant  it 
with  a  new  one,  but  he  must  study  the  underlying  controUing 


CHILDREN  S   TEETH 


211 


factors  of  dentition  and  supplement  them  where  necessary. 
The  underlying  principles  governing  successful  dentition  are 
comparatively  simple  if  assistance  is  given  before  the  teeth  are 
fully  erupted  and  their  bony  alveoli  are  in  the  formative  stage. 
The  fundamental  law  is  that  the  full  normal  width  of  the  arch 
from  sixth-year  molar  to  sixth-year  molar  must  be  maintained 
and  that  the  cusps  or  planes  of  the  upper  teeth  should  always 
bite  exterior  to  the  respective  cusps  or  planes  of  the  lower  teeth; 
that  the  anterior  cusp  of  the  lower  first  molar  should  occlude 


Fig.  123. — Left  side  of  normal  arch  of  a  boy  of  seven  years. 


anterior  to  the  upper  first  molar,  and  the  lower  four  incisors 
should  always  come  inside  of  the  upper  incisors  and  be  made  to 
evenly  assume  the  full  width  of  the  Kne  of  the  arch.  If  this  is 
accomplished  and  this  position  maintained  until  the  permanent 
lower  canines  come  in  unrotated  at  the  extreme  ends  of  the 
erupted  lower  incisors,  the  teeth  will  be  locked  in  a  normal  posi- 
tion and  will  mold  the  upper  teeth  accordingly. 

Case  No.  i  (Figs.  123-125)  represents  the  arches  of  a  boy  of 
seven  whose  teeth  fulfil  the  law.  The  formulation  of  this  law 
has  completely  revolutionized  the  science  of  straightening  teeth. 


212  MODERN  DENTISTRY 

The  teeth  of  young  growing  children  should  only  be  disturbed 
when  they  do  not  conform  to  the  tenets  of  this  law.  Teeth  that 
are  apparently  out  of  place,  but  developing  along  the  true  plan 
of  dentition  should  be  left  undisturbed  because  they  will  event- 


Fig.  1 24. — Normal  open  arches  of  a  boy  of  seven  years.  Triangle  a-b-c  is  a 
valuable  guide  in  determining  whether  the  dental  arch  is  sufficiently  wide  to  insure 
satisfactory  future  development.  It  should  be  measured  either  on  cast  or  on  the 
actual  arches  with  a  pair  of  dividers.  Base  line  a-h,  extending  from  the  anterior 
sulci  of  first  permanent  upper  molars,  should  exceed  by  15  to  20  per  cent,  either 
line  a-c  or  h-c,  which  meet  at  the  median  line  of  the  central  incisors. 

ually  straighten  themselves,  but  if  the  cutting  edge  of  an  upper 
molar  starts  to  sHp  inside  the  lower  arch,  or  the  anterior  cusp 
of  the  upper  first  molar  starts  to  slip  anterior  to  the  anterior 
cusp  of  the  lower  first  molar,  or  the  line  of  the  lower  four  in- 


CHILDREN  S    TEETH 


213 


cisors  is  not  even  and  true  and  inside  the  upper  incisors,  then 
it  becomes  the  duty  of  the  dentist  in  charge  to  correct  these 
deformities  at  once.  He  must  not  wait  until  the  canines  emerge, 
nor  must  he  wait  until  there  is  a  convenient  time  to  accompHsh 
the  work;  he  must  remedy  the  tendency  at  once  in  order  that 
normal  dentition  may  go  on  undisturbed.  In  addition  to  vio- 
lations of  the  law  just  set  forth,  there  may  be  pathologic  bone 
compHcations  or  inhibition  of  bone  development,  there  may  be 
mouth-breathing  and  adenoids,  and  various  unknown  factors 


Fig.  125. — Right  side  of  a  normal  arch  of  a  boy  of  seven  years. 


of  faulty  dentition,  but  in  90  per  cent,  of  the  cases  of  maloc- 
clusion the  sole  cause  of  serious  deformity  arises  because  the 
correct  relations  of  the  few  teeth  essential  in  the  law  just  quoted 
are  not  maintained. 

And  so,  while  it  is  wise  and  just  that  the  child  who  is  far 
advanced  in  malocclusion  should  go  to  the  orthodontist  who 
makes  a  specialty  of  this  branch  of  dentistry,  the  prevention 
of  malocclusion  should  rest  with  the  general  practitioner  of 
dentistry,  who,  watching  the  child  between  the  ages  of  four 
and  twelve,  should  see  to  it  that  the  first  upper  permanent 


214  MODERN  DENTISTRY 

molars  bite  buccally  and  posteriorly  to  the  lower  first  perma- 
nent molars,  that  the  lower  permanent  incisors  erupt  in  and 
maintain  an  unbroken  arch,  and  that  no  upper  tooth  is  ever 
allowed  to  erupt  Hngually  to  a  lower  tooth,  and  that  the  lower 
canines  erupt  unrotated  at  the  extreme  ends  of  the  perfect  hne 
of  the  lower  incisors.  Since  it  is  the  main  responsibility  of  the 
general  practitioner  of  dentistry  to  see  to  it  that  this  funda- 
mental law  is  not  allowed  to  be  transgressed,  it  shall  now  be 
specifically  pointed  out  just  how  these  tendencies  should  be 
corrected,  and  the  times  that  they  usually  appear. 

It  must  not  be  forgotten  that  inflammation  of  the  gums 
and  decay  of  the  temporary  teeth  have  a  marked  influence  on 
the  forces  governing  accurate  dentition.  If  the  first  teeth  decay, 
and  are  thereby  lessened  in  width  or  are  lost,  the  space  they 
should  occupy  is  also  lessened,  and  there  is  a  corresponding 
tendency  for  the  jaw  to  be  constricted  so  that  the  space  for  the 
second  teeth  will  be  endangered.  Also  if  the  pulps  of  the  tempo- 
rary teeth  are  diseased  or  destroyed,  the  roots  do  not  absorb 
normally  at  their  appointed  time,  and  thus  the  normal  eruption 
of  the  permanent  teeth  is  disturbed.  These  factors  alone  may 
cause  malocclusion.  Therefore  the  first  and  most  important 
obhgation  of  the  dentist  is  to  see  that  the  temporary  teeth  are 
kept  clean  and  free  from  decay.  If  they  are  in  serious  maloc- 
clusion, and  it  sometimes  happens  that  they  are,  it  may  occasion- 
ally be  necessary  to  start  at  the  age  of  four  or  five  to  coax  them 
into  position,  but  ordinarily  it  is  better  to  wait  at  least  until 
the  age  of  six  or  seven,  when  the  first  permanent  molars  and  the 
permanent  lower  incisors  have  appeared  through  the  gums. 
This  is  especially  true  because  a  perfectly  occluding  set  of  tem- 
porary teeth  does  not  by  any  means  insure  a  perfect  occlusion 
of  the  permanent  teeth,  and,  therefore,  if  there  seems  to  be  a 
fairly  normal  line  occupied  by  the  temporary  teeth  it  is  better 
to  wait;  but  if  the  temporary  teeth  are  badly  cramped  or  the 
lower  teeth  are  biting  outside  of  the  upper  teeth,  expansion  of 
the  arch  and  reduction  of  the  deformity  should  be  started  at  once. 
This  is  especially  important,  since  the  permanent  teeth  lie 
beneath  the  temporary  teeth,  and  the  adjustment  of  the  tempo- 


children's  teeth  215 

rary  teeth,  in  many  instances,  will  actually  draw  the  permanent 
teeth  into  normal  position.  Often  the  case  that  appears  very 
diflficult,  and,  without  doubt,  would  develop  most  unfortunately, 
with  a  little  study  can  be  remedied  at  once,  or  at  least  so  modified 
that  the  child  will  remedy  the  baneful  tendency  by  its  own  natural 
movements  in  biting. 

Take,  for  instance,  Case  2  (Fig.  126).  It  is  the  mouth  of  a 
little  girl  of  five  years  who  from  thumb-sucking  has  forced  out 
the  upper  incisors,  and  in  so  doing  has  pushed  back  the  entire 


Fig.  126. — Case  2,  little  girl  of  five  years  whose  jaw  has  been  forced  back  by 
thumb-sucking.  The  molars  have  the  same  relative  positions  on  both  sides  of  the 
jaw. 

lower  jaw,  as  can  be  seen  by  the  position  of  the  first  molars. 
The  extent  of  the  malocclusion  is  shown  by  the  lines  indicating 
where  the  true  occlusion  should  be.  It  looks  like  a  very  serious 
and  difficult  case,  but  it  was  remedied  in  a  very  simple,  easy  way. 
It  was  found  that  if  the  lower  jaw  was  slipped  forward,  as  in 
Fig.  127,  the  deformity  instantly  disappeared.  Bands  were  fitted 
and  cemented  on  the  lower  first  molar  with  wire  lugs  on  the  side, 
and  then  bands  were  fitted  on  the  upper  molars  with  extensions 
that  made  it  impossible  for  the  little  girl  to  close  her  mouth 
Unless  she  kept  her  jaw  forward  in  the  right  position.     It  hap- 


2l6  MODERN  DENTISTRY 

pened  that  this  Kttle  girl  had  a  strong,  persistent  bite  and  usually- 
kept  her  teeth  together,  so  this  simple  device  entirely  remedied 
her  trouble,  and  the  permanent  dentition  progressed  normally. 
If  she  had  been  a  mouth-breather  with  her  mouth  constantly 
open,  the  assistance  given  by  the  tendency  to  keep  the  teeth 
together  would  have  been  lacking,  and  the  Baker  anchorage 
would  have  been  necessary.  This  anchorage  will  be  described 
later  on.  It  was  found  of  great  advantage  to  grind  the  teeth 
with  an  engine  stone  so  that  there  would  be  accurate  articulation 
in  their  new  position.    This  is  frequently  an  essential  procedure 


Fig.  127. — Case  2  restored  to  normal  occlusion. 

in  such  cases,  and  as  the  teeth  are  to  be  lost  later  their  deformity 
is  of  no  consequence.  When  the  upper  deciduous  centrals  came 
out,  as  they  did  in  a  short  time,  the  change  to  the  new  position 
had  been  easily  accepted  by  the  child's  jaw  and  soon  became 
the  normal  position. 

Case  No.  3  (Figs.  128-130),  as  can  be  seen,  also  showed  a 
marked  dropping  back  of  the  lower  jaw  with  protrusion  of  the 
front  teeth.  In  this  instance,  as  the  child  was  only  a  month  or 
two  over  four  years  old,  it  was  decided  that  it  would  be  dangerous 
to  allow  the  deformity  to  increase  up  to  the  age  of  seven.  It  was 
found  that  the  lower  iaw  could  be  moved  forward  into  proper 


children's  teeth 


217 


Fig.  128. — Case  3,  little  girl  of  four  years  whose  lower  jaw  has  slipped  back  into 
posterior  occlusion.     Right  side. 


Fig.  129. — Case  3,  little  girl  of  four  years  whose  lower  jaw  has  slipped  back  into 
posterior  occlusion.     Left  side. 


position,  as  in  Fig.  131.  Therefore,  thin  caps  of  pure  gold  were 
adjusted  to  the  upper  canines,  and  projections  were  built  on  them 
on  the  lingual  surface  with  sponge  gold  and  solder  so  that  the 


2l8 


MODERN   DENTISTRY 


Fig.  130. — Case  3. 


Fig.  131. — Case  3  restored  to  normal  occlusion  by  gold  caps  on  the  canines. 


children's  teeth  219 

jaws  could  not  go  back  without  striking  the  projections.  In  fact, 
the  only  way  the  child  could  get  her  teeth  together  was  by  keeping 
the  jaw  forward  in  the  normal  position.  This  she  did  so  success- 
fully that  when  the  permanent  teeth  came  in  there  was  hardly 
any  further  straightening  to  be  done. 

When,  however,  as  in  Case  No.  4,  the  lower  second  molar 
on  only  one  side  of  the  jaw  is  posterior  to  its  upper  fellow,  the 
other  side  being  normal,  it  may  be  difficult  or  impossible  for  the 


Fig.  132. — Case  4,  little  girl  of  five  years  with  the  second  lower  molar  on  only  one 
side  in  posterior  occlusion,  the  left  side  being  normal. 

child  to  shift  the  jaws  so  that  the  occlusal  planes  of  both  sides 
will  engage  normally  (Figs.  132,  133).  As  the  Baker  anchorage 
is  to  be  required  in  any  event,  it  may  be  simpler  to  wait  until  the 
first  permanent  molars  appear  and  get  them  also  into  position, 
because,  as  before  stated,  when  the  temporary  molars  are  in 
normal  position  such  a  fact  gives  no  guarantee  that  the  perma- 
nent molars  will  likewise  erupt  in  normal  position.  The  only 
sure  fact  in  these  cases  is  that  when  the  occlusion  of  the  temporary 


220  MODERN  DENTISTRY 

molars  is  abnormal  the  occlusion  of  the  permanent  molars  will 
surely  be  abnormal. 

The  next  case,  No.  5,  is  t3^ical  of  a  great  number,  and  is  an 
exact  reproduction  at  an  older  age  of  the  conditions  found  in 
Case  No.  3.  If  it  is  taken  in  hand  properly  the  irregularity  is 
capable  of  easy,  permanent  remedy;  while  if  it  is  allowed  to  drift, 
it  is  impossible  to  foretell  what  deformity  may  result.  Figures 
134  and  135  show  both  sides  with  the  lower  molars  in  distal  oc- 
clusion to  the  upper,  while  the  individual  arches  in  themselves  are 


Fig.  133. — Case  4,  left  side,  showing  normal  occlusion. 

normal  in  shape.  Figure  136  shows  the  lower  jaw  extended  so 
that  the  arches  are  in  good  occlusion.  Therefore  the  only  thing 
necessary  is  to  train  the  jaws  and  coax  the  teeth  into  this  position. 
As  the  patient  had  a  tendency  to  keep  the  mouth  open,  the  method 
used  in  Cases  2  and  3  was  not  available,  so  the  Baker  anchorage 
was  used.  Since  this  anchorage  is  of  such  importance,  a  minute 
description  of  it  wiU  now  be  undertaken. 

Until  about  twenty  years  ago  it  was  the  writer's  habit  to 
make  many  curious  appliances  for  remedying  the  defects  of 


children's  teeth 


221 


Fig.  134- 


Fig.  135. 
Figs.  134,  135. — Case  5,  child  of  eight  years.    Lower  jaw  in  posterior  occlusion  to 

upper  jaw. 

irregularity,  but  since  then  he  has  accepted  the  principles  and 
appliances  advised  by  Angle,  and  therefore  the  Angle  appliances 


222  MODERN  DENTISTRY 

for  accomplishing  these  results  will  be  described.  While,  of 
course,  necessary  modifications  have  to  be  made  in  each  individual 
case,  they  should  be  made  according  to  the  principles  laid  down 
by  Angle.  The  Baker  anchorage  consists  of  appliances  shown 
in  Figs.  137  and  138 — an  expansion  arch  and  the  bands  suppHed 
with  screw-thread  and  nut  for  attaching  them  to  the  teeth. 
The  author  finds  it  better  to  make  a  simple  band  that  fits  the 
molars  to  be  moved  and  to  solder  the  tubes  on  the  side,  thus 
making  the  appliance  smoother  to  the  tongue  than  if  the  tight- 


Fig.  136. — Case  5,  teeth  in  normal  occlusion,  cure  being  accomplished  by  the 

Baker  anchorage. 


ening  screw  and  nut  were  used.  This  band  can  be  cemented 
into  position  and  the  expansion  arch  adjusted,  as  shown  in  Fig. 
138.  Little  hooks,  like  the  one  shown  in  Fig.  138,  must  be  sKpped 
on  the  upper  arch  and  soft  soldered,  so  that  they  will  be  situated 
just  opposite  the  canines.  A  couple  of  ligatures  of  silk  or  brass 
wire  should  be  passed  around  the  arch  and  incisors  so  as  to  keep 
the  arch  from  bending  under  the  traction  strain,  and  the  rubber 
bands  attached  as  in  the  illustration.  I  shall  not  go  minutely 
into  the  description  of  how  these  Angle  appliances  are  made  and 


children's  teeth 


223 


adjusted,  as  Angle's  works  are  universally  known,  and  those 
who  desire  fuller  details  are  referred  to  them. 

Suffice  it  to  say,  then,  that  the  Baker  anchorage  was  applied, 
and  in  a  few  months  the  jaws  and  teeth  permanently  took  the 
position  shown  in  Fig.  136.     Here  all  the  requirements  of  the 


Fig.  137. — Expansion  arch  and  retention  bands  devised  by  Angle. 


fundamental  law  were  fulfilled— the  lower  molars  occluded 
anterior  and  lingually  to  the  upper  molars,  the  four  lower  front 
teeth  in  even,  full  arch  occluded  Hngually  to  the  upper  teeth,  and 
there  was  every  reason  to  expect  the  permanent  canines  to  come 
into  proper  position  at  the  ends  of  the  four  lower  incisors,  which 


224 


MODERN  DENTISTRY 


they  eventually  did,  and  the  case  is  now  developing  in  good 
occlusion. 


Fig.  138. — Baker  anchorage. 


Case  No.  6  is  similar  to  Case  No.  5,  except  that  the  in- 
cisors have  not  scissored  past  each  other,  and  it  required  the 
same  appliance  and  treatment  (Figs.  139-141).  The  molar  oc- 
clusion on  the  left  side  was  normal.    When  the  lower  teeth  on 


children's  teeth 


225 


Fig.   139. — Case  6,  right  side  only  in  posterior  occlusion,  necessitating  Baker 

anchorage. 


Fig.  140. — Case  6,  showing  normal  occlusion  on  left  side. 


the^right  side  were  coaxed  forward  judiciously  the  central  and 
lateral  upper  incisors  dropped  naturally  and  permanently  into 


15 


226 


MODERN  DENTISTRY 


their  normal  positions.  It  ought  to  be  stated  here  that  where 
the  upper  and  lower  incisors  have  scissored  past  each  other 
beyond  the  limit  of  normal  occlusion  the  molars  should,  if  neces- 
sary, be  built  up  with  cement  to  permit  of  a  normal  occlusion 
of  the  front  teeth. 


u 


fe 


Case  No.  7,  as  seen  in  Figs.  142-144,  is  of  the  same  type  as 
Case  No.  4,  except  that  the  arch  of  the  upper  incisors  has  been 
broken  by  the  pressure  of  the  upper  lip.  The  same  treatment  as 
that  of  Cases  No.  4  and  5  will  suffice,  except  that  the  broken 


children's  teeth 


227 


Fig.  142.— Case  7,  malocclusion  arises  in  a  great  degree  from  irregularity  of 
lower  front  teeth  as  well  as  from  the  posterior  occlusion  of  left  lower  permanent 
molar. 


Fig.  143. —  Case  7. 


arch  of  the  upper  central  and  lateral  incisors  must  be  restored 
so  that  it  will  fit  the  lower  arch. 


228 


MODERN  DENTISTRY 


Case  No.  8  deals  with  complications  caused  by  unevenness 
in  the  line  of  the  lower  permanent  incisors.  This  sort  of  irregu- 
larity is,  by  all  odds,  the  most  common  and  requires  the  most 
careful  watching  on  the  part  of  the  dentist.  It  appears  between 
the  ages  of  seven  and  eight.  The  permanent  molars  have  erupted 
and  on  both  sides  are  in  normal  occlusion;  left  side  is  shown  in 
Fig.  145.    It  will  be  noted  that  where  the  molars  are  in  proper 


Fig.  144. — Case  7. 


occlusion  the  loss  of  the  right  deciduous  molar  is  a  handicap, 
for  the  space  must  be  maintained  until  the  permanent  bicuspid 
erupts,  but  the  principal  difficulty  lies  in  the  reconstruction  of 
the  lower  arch.  In  this  case  expansion  arches,  as  shown  in  Fig. 
137,  were  adjusted  on  both  upper  and  lower  jaws,  but  the  rubber 
loops  were  not  used,  as  the  permanent  molars  were  in  normal 


children's  teeth  229 

occlusion.  The  space  between  the  upper  temporary  canines 
was  widened  to  permit  the  occlusion  of  the  full,  even  arch  of  the 
lower  incisors  and  lower  temporary  canines,  which  alignment 
was  accompHshed  at  the  same  time  by  simply  making  the  arches 
the  size  and  shape  desired  and  drawing  the  teeth  to  them  with 
loops  of  twisted  silk  or  brass  wire  made  for  the  purpose. 

The  beauty  of  such  simple  appliances  is  to  be  found  in  the 
fact  that  they  can  also  be  used  for  retention.  Between  the  ages 
of  six  and  ten  no  attempt  at  permanent  retention  is  sensible,  as 
it  retards  development.    We  simply  get  the  teeth  into  the  posi- 


Fig.  145. — Case  8,  principal  factor  of  malocclusion  is  the  unevenness  of  lower 

incisors. 

tion  demanded  by  the  law  and  hold  them  until  they  lose  their 
tendency  to  return  to  their  old  position,  and  then  let  them  go, 
hoping  that  the  development  will  proceed  along  normal  lines. 
I  seldom  hold  any  child's  teeth  in  a  fixed  position  for  over  six 
months  at  a  time.  That  is  usually  sufficient  to  give  them  the 
proper  developmental  push.  The  general  practitioner  of  den- 
tistry is  like  a  riverman  guiding  a  log  down  the  river.  He  pushes 
the  teeth,  when  they  get  jammed  or  stalled,  out  into  the  stream  of 
natural  development,  and  feels  that  he  must  constantly  watch 
their  progress  along  the  shoals  and  eddies  of  childhood  and  pu- 


230 


MODERN  DENTISTRY 


berty  until  they  reach  the  final  jam  and  haven  in  the  perfect 
arch.  And  in  so  doing  his  task  is  easier  than  that  of  the  ortho- 
dontist. If  the  general  practitioner  of  dentistry  watches  each 
stage  of  development  his  work  is  seldom  if  ever  hkely  to  involve 
any  but  the  simplest  problems,  and  will  lead  to  perfect  results; 
while  the  orthodontist,  not  ordinarily  seeing  the  child  until  a 


Fig.  146. — Case  8.    Here  again  we  have  the  triangle  laid  out  showing  by  the  base 
line  a-b  that  the  arch  is  sufficiently  wide. 


deformity  is  well  established,  has  often  titanic  difiiculties  in  a 
period  when  developmental  forces  are  slackening,  when  the  bony 
tissues  are  mostly  formed,  for  better  or  for  worse,  and  the  demands 
of  school,  college,  and  society  are  wont  to  be  considered  by  the 
parents  of  far  more  consequence  than  the  advantages  arising 
from  straight  arches.    In  Case  8  the  child's  appliances  were  kept 


children's  teeth  231 

on  for  six  months  and  the  mother  was  instructed  to  see  that 
they  were  kept  clean — not  "brush  them,"  but  see  that  they  were 
kept  clean  by  examining  where  the  appHances  and  teeth  were 
dirty  and  cleansing  them  with  a  small  brush.  At  the  end  of  that 
time  the  appliances  were  removed  and  the  development  was 
allowed  to  proceed,  with  every  chance  of  the  haven  of  normal 
occlusion  being  reached. 

Contraction  of  the  arch  is  a  prominent  cause  of  progressive 
irregularity  both  in  the  mouth  and  nose,  and  it  should  be  noted 


Fig.  147. — Case  g.     Contracted  arch. 

and  remedied  at  the  earliest  moment  possible.  A  safe  and  practi- 
cal test  to  show  whether  a  child's  arch  should  be  expanded  is  to 
lay  out  such  a  triangle  as  is  shown  in  the  upper  arch  of  Figs. 
146  and  149.  Figure  146  represents  a  normal  width,  while  that 
of  Fig.  149  is  contracted.  The  base  line  extends  between  the 
fossae  a-h  of  the  first  permanent  molars.  The  triangle  sides  are 
obtained  by  drawing  the  Knes  a-c  and  h-c  to  the  median  Hne  at 
the  cutting  edge  of  the  central  incisors.  If  there  is  to  be  suffi- 
cient room  for  the  normal  alignment  of  the  teeth  in  the  arch  the 
base  hne,  a-h,  should  always  be  from  15  to  20  per  cent,  greater 


232  MODERN  DENTISTRY 

than  the  length  of  either  of  the  Hnes  a-c  or  h-c.  If  the  upper  and 
lower  arches  are  synchronously  expanded  by  appliances  a  little 
too  much  it  will  cause  no  harm,  for  the  erupting  teeth  will  be 
forced  into  their  proper  relations  by  the  pressure  of  the  cheeks, 
but  if  the  arch  is  contracted  there  will  not  be  sufficient  space  for 
the  imbroken  curve  of  the  front  teeth.  It  wiU  be  noted  that  al- 
though Case  No.  9  has  a  contracted  arch  its  treatment  is  practi- 
cally similar  to  that  of  Case  No.  8. 

Let  us  now  take  up  Case  No.  9  (Figs.  147-149).   Here  we  have 
a  condition  similar  to  Case  No.  8  except,  in  addition  to  the  irregu- 


Fig.  148.^ — Case  9. 

larity  of  the  teeth,  we  have  the  contracted  arch  just  mentioned. 
The  wire  expansion  arches  were  bent  so  as  to  give  the  desired 
width  a-h  from  molar  to  molar,  and  then  were  put  on  in  the  ordi- 
nary way;  then,  while  the  upper  and  lower  deciduous  canines 
were  being  rotated  and  pulled  into  position  by  means  of  twisted 
silk  tied  to  the  expansion  arch,  the  natural  arches  were  being 
spread  at  the  same  time  by  the  slow  steady  spring  of  the  expan- 
sion arch.  If  a  supplementary  spring  within  the  arch  is  needed 
in  these  cases,  it  can  be  used.  It  will  be  noted  that  the  procedures 
in  all  these  cases  were  simple  and  ordinarily  easy  of  performance 


CHILDREN  S   TEETH  233 

because  the  regulating  was  undertaken  during  the  formative 
period.  But  had  the  teeth  been  allowed  to  develop  along  ab- 
normal hues  it  is  hard  to  imagine  the  extent  of  the  irregularities 
that  might  have  resulted.    In  all  of  these  cases  only  one  type  of 


Fig.  149. — Case  9.     Here  the  base  line  of  the  triangle  a-b  is  hardly  longer  than 
either  of  the  other  two  sides,  and  the  arches  must  be  widened  15  or  20  per  cent. 


appliance  was  necessary,  namely,  the  expansion  arch,  originated 
by  Fauchard  and  perfected  by  Angle  and  Baker. 

Case  No.  lo,  as  shown  in  Figs.  150  and  151,  presents  a  problem 
almost  identical  with  that  of  Case  No.  8,  except  that  the  right  lower 
first  permanent  molar  is  in  sHghtly  distal  occlusion  to  its  upper 
fellow,  as  shown  in  Fig.  150,    On  the  left  side,  which  is  not  shown, 


234 


MODERN   DENTISTRY 


Fig.  150. 


Fig.  151- 
Figs   150,  151. — Case  10.     Malocclusion  largely  caused  by  unevenness  of  lower  in- 
cisors and  the  premature  loss  of  right  upper  first  molar. 


children's  teeth 


235 


Fig.  152. — Case  11,  abnormality  caused  by  irregularity  of  lower  incisors. 


Fig.  153.— Case  11. 

the  occlusion  is  normal.    As  will  be  seen  in  Fig.  151,  the  arch  of 
the  upper  incisors  is  good,  while  the  lower  incisors  are  jammed 


236  MODERN  DENTISTRY 

into  a  broken  line,  as  was  the  case  with  Case  No.  8.  While  it 
took  only  three  months  to  permanently  remedy  the  defects  of 
Case  No.  8,  it  took  a  year  and  a  half  to  coax  the  teeth  of  Case 
No.  10  into  normal  occlusion.  The  difference  lay,  first,  in  the  fact 
that  the  permanent  molars  of  Case  No.  8  were  in  perfect  occlusion, 


Fig.  154. — Case  11. 

while  the  right  permanent  molars  of  Case  No.  10  were  in  abnor- 
mal occlusion.  Also  the  tissues  of  the  child  of  No.  8  were  healthy 
and  showed  progressive  development,  while  in  the  case  of  No.  10 
development  of  the  tissues  was  slow,  so  that  progress  in  pulling 
the  teeth  into  shape  had  to  be  gradual  and  tedious.  The  right 
lower  temporary  canine  of  Case  No.  10  was  lost  too  soon  from 


CHILDREN  S    TEETH  237 

the  strain  of  moving,  necessitating  constant  care  and  watching 
so  that  the  space  could  be  maintained  until  the  permanent  canine 
came  into  position,  and  last,  but  of  special  consequence,  was  the 
fact  that  the  first  child  in  every  way  possible  gave  sympathetic 
assistance,  while  the  second  child  apparently  lay  awake  nights 
thinking  how  she  could  devise  fancy  bites  that  would  break 
the  rubber  bands  and  loosen  the  apparatus.  Needless  to  say 
progress  was  very  slow  until  one  day  the  child  was  caught  delib- 


Fig.  i55.-^Case  12,  irregularity  caused  by  protrusion  of  the  frenum  of  lip 
between  upper  central  incisors  and  also  a  slipping  of  left  upper  teeth  inside  of  left 
lower  teeth. 

erately  biting  the  rubber  band  that  had  just  been  adjusted.  It 
was  with  difficulty  that  the  indulgent  mother  was  made  to  realize 
that  the  secret  antagonism  of  the  child  was  the  chief  cause  of 
the  slow  progress.  But  when  this  was  reahzed  and  remedied, 
the  case  was  finished  without  undue  delay,  and  it  is  strongly 
recommended  that  all  dentists  be  on  their  guard  against  such 
idios3Tacrasies.     - 

Case  No.  ii  (Figs.  152-154)  is  similar  to  No.  8.  The  occlusion 
of  the  first  permanent  molars  was  normal.    The  expansion  arches 


238  MODERN  DENTISTRY 

were  adjusted,  the  distance  between  the  canines  slowly  increased 
to  give  room  to  the  lower  teeth,  and  the  lower  four  incisors  were 
moved  to  a  normal,  even  curve,  with  the  deciduous  canines  at 
the  ends  in  their  normal  positions. 

The  irregularity  of  Case  No.  1 2  is  due  to  two  factors :  First, 
as  is  shown  in  Figs.  155-157,  the  upper  left  temporary  teeth  from 


Fig.  156. — Case  12. 

the  canines  back  are  biting  inside  the  lower  left  temporary  teeth; 
this  causes  a  narrowing  of  the  upper  arch,  as  can  be  seen  by  the 
relatively  short  line  a-b  (Fig.  156).  This  condition  can  be  rem- 
edied by  upper  and  lower  expansion  bars.  The  second  factor 
in  this  case  is  a  cause  of  distortion  that  has  not  been  mentioned 
before,  and  that  will,  if  left  undisturbed,  constantly  defeat  our 


children's  teeth  239 

best  efforts.  This  factor  is  the  extension  of  the  frenum  of  the 
lip  between  the  upper  central  incisors  in  between  the  two  superior 
maxillary  bones,  causing  a  constantly  increasing  space  between 
the  upper  central  incisors  and  a  tendency  for  them  to  rotate. 
Again  we  must  thank  Dr.  Angle  for  the  discovery  of  the  cause 
of  this  deformity  and  for  the  remedy.  This  frenum  must  be 
extirpated,  for  otherwise  the  movement  of  the  lip  pulling  on 
the  spongy  tissue  between  the  front  teeth  will  always  tend  to 


Fig.  157. — Case  12. 

distort  them,  no  matter  how  often  we  bring  the  teeth  together 
and  no  matter  how  long  we  hold  them  in  normal  position. 

Extirpation  of  the  Frenum. — Novocain  and  suprarenin  are 
injected  into  the  frenum,  and  also  deep  in  between  the  supe- 
rior maxillary  bones,  until  the  adjacent  region  is  white  and  insensi- 
tive. Then  the  frenum  is  dissected  up  to  the  junction  of  the  gum 
and  lip.  After  that  is  done  a  fissure  bur.  No.  17  B.  &  S.  gage,  is 
plunged  into  the  articulation  of  the  superior  maxillary  bones 
and  brought  down  along  the  median  line  until  the  interdental 
space  between  the  upper  central  incisors  has  been  completely 


240  MODERN  DENTISTRY 

bored  out  and  the  membranous  junction  between  the  bones 
has  been  completely  severed  and  drilled  away.  It  is  most  impor- 
tant that  the  point  at  which  the  bur  enters  should  be  high  up 
in  the  median  line.  After  the  bleeding  has  stopped  a  drop  or  two 
of  trichloracetic  acid  can  be  flowed  into  the  wound  to  completely 
cauterize  the  remaining  shreds.  After  the  wound  has  healed 
we  can  then  complete  the  case  with  the  expansion  arch,  as  pre- 


Fig.  158. — Case  12  completed. 

viously  described.  It  wiU  be  noted  from  the  size  of  the  triangle 
base  that  the  arch  is  slightly  contracted.  Figure  158  represents 
the  case  four  years  later,  showing  the  permanency  of  the  operation. 
Case  No.  13,  as  is  shown  in  Figs.  159-161,  and  Case  No.  14, 
Figs.  162,  163,  are  compHcated  by  the  frenum  growing  between 
the  upper  central  incisors.  When  this  is  removed,  as  just  de- 
scribed, there  will  be  no  difficulty  in  making  the  teeth  perma- 
nently assume  their  normal  occlusion. 


children's  teeth 


241 


Fig.  159. — Case  13  irregularity  caused  by  frenum  of  lip  growing  between  upper 

central  incisors. 


Fig.  160. — Case  13. 


16 


242 


MODERN  DENTISTRY 


Impaction  of  Teeth.— We  now  come  to  the  discussion  of 
irregularities  compKcated  or  caused  by  the  impactions  of  perma- 
nent teeth,  as  is  shown  in  Case  No.  15,  Figs.  164-166.  This 
is  a  very  interesting  case,  and  at  first  glance  seems  normal. 
The  molars,  upper  and  lower,  are  in  proper  occlusion  and  the 
teeth  appear  to  be  within  the  influences  of  their  respective 
planes.     But  a  closer  inspection  will  show  that  the  temporary 


Fig.  161. — Case 


13- 


upper  canines  are  still  in  position,  with  great  widening  of  the 
spaces  between  the  upper  lateral  and  central  incisors.  An  x-ray 
showed  that  the  permanent  canines  had  been  diverted  Hngually 
by  the  ends  of  the  roots  of  temporary  canines  that,  unfortunately, 
were  not  absorbing  normally.  The  permanent  canines,  there- 
fore, were  forced  within  the  arch  and  were  being  held  there  by  the 
thick,  rigid  palatal  process  of  the  superior  maxillary  bones. 
Figure  164  shows  two  sHght  elevations,  marked  with  rings,  beneath 


children's  teeth 


243 


Fig.   162. — Case  14,  complicated  by  frenum  of  lip  penetrating  between  upper 


Fig.  163. — Case  14. 


244  MODERN  DENTISTRY 

which  the  impacted  teeth  lie.  The  patient  was  a  girl  of  fourteen 
years.  The  temporary  canines  were  extracted  and  the  gums 
and  bone  over  the  impacted  canines  were  cut  and  burred  away 
and  the  tips  of  the  impacted  teeth  exposed.  This  operation  was 
performed  under  nitrous  oxid  gas  and  oxygen,  but  the  author  now 
prefers  local  anesthesia,  as  previously  described.  Trichloracetic 
acid  was  applied  immediately  after  the  operation,  and  in  two 


Fig.  164. — Case  15,  deformity  caused  by  impacted  canines. 

days  the  gum  and  membrane  over  the  tips  of  the  impacted 
canines  had  completely  cleared  away  and  the  enamel  of  the 
canines  was  in  plain  view.  An  expansion  arch  was  then  placed 
on  the  upper  teeth  and  from  it  rubber  loops  were  judiciously 
attached  to  the  laterals,  pulling  mesially,  and  also  to  the  first 
bicuspids,  pulling  distally  toward  the  molars,  and  by  these  rubber 
ligatures  the  full  space  required  for  the  passage  of  the  canines 


CHILDREN  S  TEETH 


245 


Fig.  165.— Case  15. 


Fig.  166. — Case  15. 


from  the  interior  to  the  exterior  of  the  arch  was  obtained  in  due 
time.  Then  a  How  screw  was  inserted  in  the  lingual  plane"* of 
each  canine  near  the  tip,  and  rubber  loops  fastened  to  the  screws 


246 


MODERN  DENTISTRY 


Fig.  167. — Angle  device  for  causing  eruption  of  an  unerupted  misplaced  canine. 


Fig.  168. — Case  16,  girl  of  ten  years.  Malocclusion  caused  principally  by 
early  loss  of  temporary  teeth,  resulting  in  impaction  of  upper  right  canine  marked 
by  circle  (A)  and  lower  first  bicuspid  marked  by  circle  (B). 


and  carried  around  the  expansion  bar  and  back  to  the  screw. 
In  this  way  the  canines  were  pulled  down  and  through  the  space 
formerly  occupied  by  the  deciduous  canines  that  had  been  ex- 


CHILDREN  S   TEETH 


247 


tracted.  When  the  canines  were  brought  into  a  position  external 
to  the  arch  the  bands  were  removed  and  the  teeth  came  into 
normal  occlusion  by  their  own  propulsive  force.  If  they  had 
not  come  properly,  the  ingenious  device  of  Dr.  Angle  shown  in 


Fig.  169. — Case  16. 


Fig.    167  would  have  been  necessary.     When  the  teeth  were 
erupted  the  screws  were  removed  and  the  cavities  filled. 

Case  No.  i6  represents  a  serious  deformity  in  a  Httle  girl  of 
ten  years  arising  primarily  from  the  lack  of  development  caused 
by  measles  during  infancy,  and  scarlet  fever  at  the  age  of  four. 
The  marks  of  these  diseases  can  readily  be  seen  by  examining 


248  MODERN  DENTISTRY 

the  incisors  and  canines  in  Figs.  168-170.  In  addition  to  injury 
done  to  the  unerupted  teeth  by  the  skin  diseases,  it  will  be  noted 
that  irregularity  arises  primarily  from  the  premature  loss  of 
the  temporary  upper  canine  on  the  right  side  and  of  the  tempo- 
rary first  lower  molar  on  the  left  side.  The  loss  of  these  two  teeth 
caused  the  permanent  lateral  incisor  on  the  right  side  to  fall 
toward  the  first  molar,  impacting  the  permanent  canine,  which  is 
located  by  the  circle  A,  Figs.  168-170.  The  loss  of  the  lower  left 
first  temporary  molar  caused  a  contraction  of  the  arch  which 


Fig.  170. — Case  16. 

resulted  in  the  impaction  of  the  first  lower  bicuspid,  as  located 
by  the  circle  B,  Figs.  168,  169.  The  lesson  to  be  learned  from 
this  case  is  twofold:  First,  if  the  temporary  teeth  had  been 
preserved  there  would  have  been  no  malposition;  second,  if  the 
patient  had  come  for  treatment  before  the  age  of  eight  the 
deformity  could  have  been  remedied  in  months,  whereas  it  took 
years  to  bring  the  teeth  permanently  into  proper  position.  It 
will  be  noted  in  Figs.  168  and  170  that  the  first  molars  are  in 
normal  occlusion  and  in  Fig.  169  that  the  arches  are  not  con- 


children's  teeth 


249 


Fig.  171.— Case  16. 


Fig.  172. — Case  16,  at  the  age  of  twelve. 


stricted.     The  expansion  bands  were  put  on  and  the  arches 
slowly  and  carefully  expanded  into  normal  shape  in  a  period  of  a 


250 


MODERN  DENTISTRY 


year  and  a  half.  During  that  time  the  impacted  teeth  came 
through  the  gum  by  their  own  force,  as  in  Case  No.  15,  and  took 
the  desired  positions  (Figs.  1 71-173),  In  Fig.  172  it  will  be  noted 
that  a  platinum  cap  has  been  placed  upon  the  right  upper  lateral 
incisor,  so  as  to  enable  it  to  maintain  itself  in  the  arch  by  a  safe 


Fig.  173. — Case  16. 


occlusion  with  the  lower  teeth.  Nothing  was  done  except  to 
expand  the  arches  and  to  make  space  where  the  temporary  teeth 
had  been  prematurely  lost.  Later  on  the  tips  of  the  incisor  and 
canines  were  restored  by  porcelain  so  that  perfect  occlusion 
was  obtained  as  in  Figs.  174-176.  These  casts  were  taken  some 
years  after  the  case  was  completed. 


CHILDREN  S   TEETH 


2^1 


Fig.  174.— Case  16,  ten  years  later. 


Fig.  175.— Case  16. 


252 


MODERN  DENTISTRY 


Fig.  176. — Case  16. 


Fig.  177. — Case  17,  irregularity  caused  by  general  malnutrition  which  resulted  in 
a  lack  of  bone  development. 


Malnutrition. — Case  No.  17  (Figs.  177-179)  shows  a  case  of 
faulty  occlusion  and  lack  of  development  due  to  malnutrition 
in  the  upper  jaw.    It  required  three  years  to  expand  the  upper 


CHILDREN  S   TEETH 


253 


Jaw  to  symmetry  with  the  lower  jaw,  which  was  fairly  normal. 
The  malnutrition  was  caused  by  measles  at  the  age  of  four,  from 
the  effects  of  which  the  child  did  not  recover  for  years.  The 
child  was  eight  years  old  when  the  case  was  undertaken.  Ex- 
pansion arches  were  used  and  the  growth  of  the  upper  arch 
stimulated  by  slow  expansion  for  a  period  of  six  months;  then 
the  appHance  was  removed  and  the  bone  allowed  to  develop  as 
it  would  for  another  six  months.    This  procedure  was  repeated 


Fig.  178. — Case  17. 


at  six-month  intervals  for  three  years,  during  which  time  care 
was  taken  that  the  child  was  properly  nourished  and  given 
judicious  exercise.  At  the  end  of  this  time  the  jaw  was  quite 
normal,  and  the  teeth  in  good  occlusion.  This  is  a  striking 
illustration  of  the  fact  that  there  need  be  no  such  thing  as  a 
permanently  small  jaw,  from  which  teeth  have  to  be  extracted, 
if  the  irregularity  is  discovered  in  early  childhood.  This  case 
proves  the  fundamental  law  that  the  face  develops  to  the  teeth, 


254 


MODERN  DENTISTRY 


not  the  teeth  to  the  face;  and  if  the  teeth  are  placed  in  perfect 
occluding  arches  during  the  developmental  period  there  will  be  a 


Fig.  179. — Case  17. 


Fig.  180. — Case  18,  finished  case  of  orthodontia  where  upper  lateral  incisors  are 

missing. 

corresponding  development  in  the  formation  of  the  profile  and 
face  generally. 


CHILDREN'S   TEETH 


25: 


Case  No.  i8  presents  a  very  interesting  complication  (Figs. 
180-182).  When  the  patient  was  seven  years  old  she  was  so 
poorly  developed  that  there  was  no  possibility  of  the  upper  jaw 
ever  developing  to  meet  the  demands  of  the  dental  arch.  The 
lower  jaw  was  fairly  normal.  In  addition  to  the  poor  development, 
the  right  upper  permanent  lateral  incisor  was  missing  and  the 
left  was  a  mere  peg.    The  restoration  of  the  permanent  lateral 


Fig.  181. — Case  18. 


incisors  by  bridgework  was  impossible  at  that  age.  So  the  rudi- 
mentary upper  lateral  incisor  was  extracted.  This  necessitated 
a  corresponding  contraction  of  the  lower  jaw.  The  lower  first 
bicuspids  were,  therefore,  extracted.  If  the  lower  lateral  incisors 
had  been  extracted  the  resulting  arch  would  have  been  V  shaped 
and  would  have  consequently  destroyed  the  contour  of  the  cheeks. 
By  thus  extracting  the  bicuspids  the  lower  normal  arch  from 


256  MODERN  DENTISTRY 

canine  to  canine  was  maintained  and  was  the  means  of  making 
the  upper  arch  appear  normal.  The  upper  canines  were  allowed 
to  come  in  next  to  the  upper  central  incisors,  and  the  lower 
canines  and  incisors  were  drawn  back  until  the  space  formerly- 
occupied  by  the  incisors  was  filled.  Care  was  taken  that  the 
normal  curve  of  the  incisors  and  canines  was  maintained.  The 
sharp  points  were  taken  off  the  upper  canines  so  as  to  make  them 
look  somewhat  like  laterals,  and  the  first  bicuspids  gave  the 
appearance  of  very  presentable  canines.  Figures  180-182  show 
the  very  satisfactory  result.     In  addition  to  the  adjusting  of 


Fig.  182. — Case  18. 

the  teeth  the  child  was  given  a  diet  containing  large  amounts 
of  fat  and  cream,  and  the  necessity  of  outdoor  exercise  was 
emphasized. 

This  chapter  will  be  concluded  with  the  reiteration  of  the 
fact  that  the  dentist  should  acquaint  himself  with  the  law  govern- 
ing the  correct  occlusion  of  children's  teeth,  and  then  he  should  see 
to  it  that  after  the  age  of  seven  especially  the  teeth  are  made  to 
conform  to  the  law.  The  distance  from  fossa  to  fossa  of  the 
first  upper  permanent  molars  should  be  15  to  20  per  cent,  more 
than  the  distance  from  the  fossa  to  the  median  Hne  of  the  central 


children's  teeth  257 

incisors.  The  upper  teeth  must  always  bite  exteriorly  to  the  lower 
teeth.  The  first  lower  molars  must  occlude  anteriorly  with  the 
upper  first  molars,  and  the  lower  incisors  must  occupy  an  unbroken 
even  curve  in  the  arch,  so  that  the  canines  will  erupt  at  the  ends 
of  the  incisor  line,  occupying  their  full  width  in  the  arch.  And  if 
the  incisors  scissor  past  each  other,  judicious  filhngs  or  caps 
should  be  placed  on  the  molars,  so  that  the  teeth  will  have  space 
to  be  brought  into  proper  occlusion.  The  ingrowing  frenum 
must  be  eradicated  when  it  appears  and  the  upper  teeth  coaxed 
into  position  if  necessary. 

And  it  is  of  greatest  importance  that  the  child's  teeth  are 
kept  clean  and  consequently  free  from  decay,  so  that  the  full 
space  occupied  by  the  temporary  teeth  will  be  maintained, 
and  so  that  the  roots  of  the  deciduous  teeth,  instead  of  becoming 
infected  and  necrotic,  will  remain  healthy  and  admit  of  normal 
absorption. 
17 


CHAPTER  IX 

CROWNS 

Pin  Crowns,  Band  Crowns,  Gold  and  Porcelain  Inlay  Crowns. 
Advantages  and  Disadvantages  of  Each 

The  artificial  crown  has  been  a  great  blessing  and  a  great 
curse  to  mankind.  Properly  made  it  is  the  means  by  which  a 
broken  or  decayed  tooth  is  efiiciently  and  artistically  restored  to 
symmetry  and  usefulness.  But  if  it  defies  the  law  of  cleanHness 
and  there  is  not  exact  gum  marginal  adjustment,  it  may  be 
the  direct  cause  of  innumerable  serious  organic  diseases. 


Fig.  183. — Pin  crown.' 


Band  crown. 


Crowns  are  divided  into  three  classes:  the  pin  crown,  the 
band  crown,  and  the  inlay  crown.  The  pin  crown  is  one  that 
depends  upon  a  pin  or  dowel  for  attachment  to  the  root,  as  in 
Fig.  183.  A  represents  the  crown,  B  the  root,  C  the  pin  or  dowel. 
The  band  crown  is  one  that  depends  for  its  stabihty  on  a  band 
attached  to  the  crown  that  hugs  the  head  of  the  root  like  a  ferrule, 
as  in  Fig.  184.  A  represents  the  crown,  B  the  root,  C  the  band, 
which  in  this  instance  is  attached  to  the  porcelain  crown  by  a  pin. 

258 


CROWNS 


259 


The  inlay  crown  is  one  that  is  attached  to  the  root  by  means  of 
an  inlay  as  in  Fig.  185.     A  represents  the  crown,  B  the  molar 


Fig.  185. — Inlay  crown. 

roots,  C  the  inlay  that  is  attached  to  the  crown  and  enters  into 
the  upper  body  of  the  root,  giving  anchorage  after  the  manner 


Fig.   187. — Inlay-band   crown:  A    represents  porce- 
lain crown;  B,  root  with  cavity  prepared  for  inlay  and  gum 
Fig.  186.— Pin-band      margin  sloped  properly  for  reception  of  band;  C,  gold  inlay 
crown.  made  in  hollow  porcelain  crown;  D,  band  and  gold  inlay 

that  is  to  make  attachment  to  root;  E,  orifice  filled  in  with 
solder  by  which  upper  and  lower  inlays  are  soldered  to- 
gether; F,  grooves  for  reception  of  cement  by  which  fixture 
is  finally  secured  into  position.  This  method  makes  it  pos- 
sible to  attach  porcelain  without  subjecting  it  to  heat. 

of  inlays.  Of  course,  these  three  methods  of  attachment  are 
capable  of  bemg  used  separately  or  in  various  combinations, 
but  we  designate  the  type  of  crown  according  to  whichever 


26o 


MODERN  DENTISTRY 


attachment  predominates.  In  addition  to  the  simple  pin,  band, 
and  inlay  crowns,  the  band  and  pin  can  be  used  in  combination 
(Fig.  i86) ;  or  the  inlay  and  band  (Fig.  187) ;  or  the  inlay  and  pin 
(Fig.  188). 

The  Pin  Crown. — ^The  pin  crown  and  the  inlay  crown  con- 
form to  the  exact  contour  of  the  tooth  at  the  gum,  and  therefore 
are  to  be  preferred  wherever  the  root  is  sufhciently  strong  and 
large  to  insure  an  anchorage  that  will  not  compel  too  great 
sacrifice  of  root  structure.  The  band  crown,  holding  as  it  does 
from  without,  will  support  a  weak  root  against  external  stress 
to  a  remarkable  degree,  but  it  has  a  serious  disadvantage  in  that 
there  is  great  possibility  of  its  impinging  on  the  gum  (Fig.  189), 
leaving  sharp  knife  edges  that  lacerate  the  tissues  every  time 
the  tooth  moves  in  its  elastic  peridental  membrane  under  the 


Fig.  188. — Pin-inlay  crown 


Fig.  189. — Band  crown  with  improp- 
erly constructed  band. 


shock  of  mastication.  This,  of  course,  need  not  be  so,  as  will  be 
presently  pointed  out,  but  it  is  a  danger  against  which  the  best 
mechanic  must  always  be  on  his  guard,  and  it  is  the  condition 
that  actually  occurs  in  the  vast  majority  of  cases.  Theoretically, 
the  band  that  projects  below  the  gum  at  the  neck  of  a  tooth  can, 
by  careful  shaping  of  the  root,  be  made  perfectly  smooth  with 
the  contour  of  the  tooth,  but  practically  this  is  not  so.  The 
root  projects  from  the  gum  as  in  Fig.  190.  It  is  therefore  im- 
possible to  fit  a  band  to  it  that  will  not  project  into  the  soft 
tissues,  as  in  Fig.  191,  unless  the  sides  of  the  head  of  the  root 
have  been  carved  and  trimmed  as  in  Fig.  192,  and  even  then  it 
is  always  a  question  whether  the  band  does  not  project  too  far, 
causing  the  edge  to  penetrate  the  surrounding  gum  and  bony 
tissues.    The  most  expert  dentist  cannot  trim  a  root  and  fit  a 


CROWNS  261 

band  under  the  gum  and  be  sure  that  the  sharp  edge  of  metal 
does  not  project  enough  to  cause  irritation  and  consequent 
infection  every  time  the  tooth  springs  under  the  impact  of 
mastication.  If  this  is  true  in  the  work  of  the  most  expert,  how 
surely  must  it  be  so  with  the  average  operator!  Let  each  dentist 
remember  the  ill-fitting  bands  he  has  deprecatingly  observed 
on  the  crowns  made  by  another  dentist;  let  him  remember  the 
crowns  made  by  himself  that  at  the  time  he  thought  were  beauti- 
fully fitted,  but  which  subsequent  events  and  the  forceps  per- 
mitted him  to  examine  out  of  the  mouth,  to  his  mortification 
and  chagrin. 

The  fitting  of  a  band  to  the  neck  of  the  root  under  the  gum 
can  be  likened  to  the  well-known  game  of  drawing  a  pig  on  paper 
with  the  eyes  closed.     The  general  outHnes  of  the  pig  can  be 


Fig.  191.  Fig.  192. 


drawn  with  a  fair  degree  of  accuracy,  but  the  characteristic 
details  are  just  as  hard  to  get  as  are  the  minute  indentations 
and  curves  of  the  root.  Yet,  in  spite  of  these  serious  objections, 
no  experienced  operator  will  say  that  the  band  crown  should  never 
be  used.  In  bridge  work  or  in  fractured  or  badly  decayed  roots 
it  fills  a  want  at  times  that  can  hardly  be  supplied  by  any  other 
device.  But  when  we  use  it  let  us  recognize  its  dangers  and  avoid 
them;  let  us  admit  that  the  best  fitting  band  crown  forms  a  ledge 
at  the  gum  margin,  and  the  seriousness  of  this  danger  will  depend 
entirely  upon  how  thoroughly  the  patient  cleanses  the  mouth  and 
how  prone  the  oral  tissues  are  to  accept  contamination.  The 
best  way  to  avoid  this  danger  is  to  trim  the  root  head  to  a  smooth, 
slightly  sloping  cone  (Fig.  193),  having  first  built  up  the  root 
where  necessary  with  amalgam  so  that  it  projects  above  the  gum. 
By  this  expedient  the  band  can  be  brought  to  the  gum  and  not 


262 


MODERN  DENTISTRY 


below  it.  And  thus,  by  lifting  the  free  margins  of  the  gum,  the 
edge  of  the  crown  can  be  examined  after  it  is  actually  cemented 
into  place,  and  any  projection  or  roughness  can  be  carefully 
polished  away  because  it  can  be  actually  seen.  But  this  pro- 
cedure will  be  mentioned  later  when  the  methods  of  making 
band  crowns  wUl  be  discussed  more  specifically.  If,  then,  the 
band  crown  ordinarily  has  such  potentialities  for  infection,  it  is 
incumbent  upon  us  to  avoid  its  use  in  all  crowns  whenever 
sufficient  anchorage  can  be  obtained  to  obviate  the  danger 
either  of  loosening  the  cement  or  fracturing  the  root. 

The  anchorage  for  the  simple  pin  crown  can  be  obtained  in 
every  instance  where  the  root  is  solid  and  undecayed  below  the 


Fig.  193. — Decayed  or 
fractured  root  restored 
with  screw  pin  and  amal- 
gam. 


Fig.  194. — Pin  crown 
with  notch  to  fit  head  of 
root. 


Fig.  195. — Pin  crown 
supported  by  gold  ledge 
on  lingual  side  of  head  of 
root. 


edge  of  the  gum.  With  the  upper  central  and  lateral  incisors 
and  canines  the  face  of  the  root  should  be  formed  into  a  notched 
wedge,  with  the  notch  on  the  lingual  aspect,  so  that  the  head 
of  the  root  will  support  the  front  wall  against  fractures  from  mas- 
tication (Fig.  194).  A  represents  finished  crown,  B  the  carved 
root,  C  the  outline  of  the  pin,  D  the  gum  Hne.  For  with  the  upper 
incisors  and  canines  the  force  of  mastication  is  ordinarily  applied 
to  the  pin  crown  so  as  to  drive  the  pin  against  the  front  wall  of 
the  excavated  root,  and  fractures  are  frequently  the  result  of  such 
a  combination.  But  if  the  stress  is  supported  by  the  notch,  as 
described,  or  by  a  ledge  (Fig.  195)  in  the  Kngual  aspect  of  the 
root,  the  danger  of  dislodgment  through  a  spHtting  of  the  root 
is  entirely  eliminated.     A  represents  the  crown,  B  the  carved 


CROWNS 


263 


root,  C  outline  of  pin,  D  gum  line,  E  gold  support  or  ledge  on 
back  of  root. 

The  method  of  making  these  crowns  is  as  follows:  The  root 
is  reamed  to  fit  the  pin,  which  should  be  made  of  iridioplatinum 
wire  or  platinized  gold  wire,  and  the  head  of  the  root  ground,  as 
shown  in  Fig.  196.  Then  the  pin  should  be  adjusted  to  the  reamed- 
out  root  canal  and  a  countersunk  crown  adjusted  and  ground  so  as 
to  closely  fit  the  labial  margin  of  the  root,  but  on  the  back  or 
lingual  aspect  a  space  should  be  left  as  shown  in  Fig.  197.  Then 
the  porcelain  crown  should  be  removed  from  the  pin  to  which 
it  is  finally  to  be  cemented,  and  the  pin  should  be  removed  from 
the  root  and  barbed  with  a  knife.    Then  platinum  foil,  o.ooi  inch. 


Fig.  196. — Root  notched 
lingually  to  receive  labial 
stress  of  pin  crown. 


Fig.  197. — Pin  crown 
in  position  preparatory 
to  packing  in  moss  fiber 
gold. 


Fig.  198. — Pin  crown 
in  position  with  moss 
fiber  gold  packed  in  posi- 
tion, as  shown  by  D. 


or  pure  gold  foil,  0.003  inch,  should  be  burnished  to  the  head  of 
the  root  and  the  pin  punched  through  it  into  the  root  canal. 
The  pin  and  foil  should  then  be  removed  together  and  soldered. 
The  pin,  cap,  and  porcelain  crown  should  be  placed  in  position, 
and  while  the  crown  is  firmly  held  by  the  left  hand  or  by  an  as- 
sistant, sponge  gold  should  be  firmly  packed  into  the  space 
remaining  between  the  crown  and  the  foil  resting  in  the  head  of 
the  root,  as  in  Fig.  198.  A  represents  the  crown,  B  the  root,  C 
the  platinum  pin  shown  by  the  dotted  lines,  and  D  represents  the 
sponge  gold  packed  into  the  aperture  between  the  head  of  the 
root  covered  by  the  platinum  foil  and  the  crown.  The  porcelain 
crown  is  then  removed  from  the  pin,  and  the  pin,  foil,  and  con- 
densed sponge  gold,  appearing  as  in  Fig.  199,  are  carefully  re- 


264 


MODERN  DENTISTRY 


moved  by  a  pair  of  pliers.  A  little  borax  is  then  placed  upon  the 
lingual  aspect  of  the  sponge  gold,  as  designated  by  the  arrow, 
and  pieces  of  2  2 -karat  gold  solder  flowed  into  the  sponge  gold 
that  is  to  go  next  to  the  porcelain,  otherwise  the  porcelain  when 
replaced  upon  it  will  not  fit.  The  solder  should  fill  the  interstices, 
not  encroach  upon  the  outside  of  the  sponge  gold  except  on  the 
lingual  aspect,  where  the  small  pieces  of  solder  are  first  laid  for 
fusing.  If  the  sponge  gold  has  been  thoroughly  packed,  as 
described,  there  will  be  no  difficulty  in  removing  the  pin,  plati- 
num foil,  and  sponge  gold  all  in  one  undisturbed  piece,  and  the 
soldering  can  be  readily  done  in  the  Bunsen  burner.  When 
the  soldering  is  completed  the  tooth  can  be  cemented  to  it  (Fig. 
200).    The  gold  back  can  then  be  polished  and  the  crown  ce- 


•^ 


Fig.  199. — Pin  and 
gold  support  against 
labial  stress. 


Fig.  200. — Pin  and 
gold  support  and  porce- 
lain crown  cemented  to- 
gether. 


Fig.    201. — Root  ready 
to  receive  crown. 


mented  to  the  root  with  Harvard  or  silicious  cement,  as  desired. 
Before  finally  cementing  it  into  its  position  on  the  root  it  is  wise 
to  remove  the  platinum  from  the  labial  portion  of  the  crown  so 
that  it  may  not  cause  a  discoloration  after  the  cement  has  set. 
In  such  a  case  as  this  it  is  well  to  fill  the  root  canal  with  Harvard 
cement  and  place  silicious  cement  on  the  face  of  the  porcelain 
and  platinum  around  the  pin.  Thus,  when  the  crown  is  shoved 
home,  we  have  the  adhesiveness  of  the  Harvard  cement  in  the 
root  canal  and  the  insolubility  and  beauty  of  the  silicious  cement 
to  act  as  an  invisible,  permanent  bond  between  the  root  and  the 
cap.    Sometimes  in  making  the  pin  crown  it  is  advisable  to  make 


CROWNS  265 

a  stiff  shoulder  of  gold  at  the  lingual  edge  of  the  root,  instead  of  a 
notch  in  the  middle,  as  in  Fig.  202.  By  this  means  the  entire 
side  thrust  of  the  lower  teeth  is  sustained  evenly  by  the  pin  and 
shoulder,  making  a  fracture  of  the  front  wall  of  the  root  practi- 
cally impossible.  When  the  root  is  perfectly  strong,  and  the 
force  of  mastication  is  such  as  not  to  make  too  great  a  lateral 


Fig.    202.— Pin    crown  Fig.    203.— Pin   crown  Fig.          204.— Wedge- 

with    gold   half    cap    or  with      direct      occlusion  shaped     head     of     root 

band  on  Imgual  side  of  that  makes  a  strong  fix-  with  adjusted  pin  crown, 

root.  ture. 

strain,  as  in  Fig.  203,  a  simple  porcelain  crown  with  a  pin  is 
usually  a  satisfactory  and  permanent  operation.  In  such  pro- 
cedures it  is  wise  wherever  possible  to  shape  the  head  of  the 
root  in  the  form  of  a  wedge  or  with  a  notch  toward  the  side  of 
the  root  on  which  the  lateral  strain  of  mastication  is  to  be  expected 
(Fig.  204).    For  instance,  if  the  occlusion  is  as  shown  in  Fig.  205, 


266 


MODERN  DENTISTRY 


the  force  of  mastication  will  obviously  have  a  lateral  stress  in 
the  direction  of  the  arrow,  and  the  notch  should,  therefore,  be  as 
indicated,  so  that  it  will  counteract  the  stress.  If  the  stress 
should  come  on  the  other  side  the  notch  obviously  should  be 
trimmed  the  other  way.  The  pin  being  separate  from  the  crown 
is  a  great  advantage  in  adjusting  the  porcelain  to  the  head  of 
the  root,  and  with  the  aid  of  the  modern  silicious  cements  the 
head  of  the  root  and  the  crown  do  not  have  to  be  so  perfectly 
adapted  as  formerly.     For  instance,  a  crown  and  root  can  be 


Fig.  206. — Root  and 
crown  roughly  notched 
to  increase  stability. 


Fig.  205. — Root 
notched  so  as  to  min- 
imize the  danger  of  frac- 
ture from  side  pressure. 


Fig.  207. — Method  of 
cementing  a  crown  and 
root  so  that  an  insoluble 
cement  may  be  at  the 
crown  and  root  margins, 
while  the  more  adhesive 
phosphate  of  zinc  cement 
may  hold  the  pin  in  posi- 
tion to  the  root. 


shaped  approximately  as  in  Fig.  206,  and  the  pin  cemented  into 
the  porcelain  in  its  proper  relation  to  the  root.  The  silicious 
cement  of  the  proper  color  should  then  be  selected  and  mixed 
to  a  doughy  consistency,  and  any  good  slow-setting  phosphate 
of  zinc  cement  should  also  be  mixed  to  a  creamy  consistency 
and  injected  into  the  canal  with  a  Jiffy  tube.  Then,  before 
the  cement  can  set,  the  sihcious  cement  should  be  placed  around 
the  porcelain  base  of  the  crown  and  neck  of  the  pin,  and  the 
crown  should  at  once  be  shoved  home,  giving  an  adhesive  cement 


CROWNS  267 

in  the  canal  against  the  pin,  and  an  insoluble,  invisible  cement  as 
a  joint  where  the  porcelain  and  root  join,  as  in  Fig.  207.  A  repre- 
sents porcelain  crown  ground  to  fit  approximately  the  notched 
root  B.  C  represents  the  platinum  point  that  extends  into  the 
porcelain  crown  and  the  root.  It  should  be  remembered  that 
real  grooves,  not  scratches,  should  be  made  in  the  root  canal  and 
deep  nicks  in  the  pin  so  that  the  cement  will  act  as  a  dowel  as 
well  as  an  adhesive.  If  the  occlusion  is  exaggerated,  so  that  a 
great  side  thrust  is  inevitable,  it  is  sometimes  possible  and 
advisable  to  grind  off  the  lower  tooth  so  as  to  make  the  masticat- 
ing force  more  end  to  end.  In  fact,  this  should  always  be  done 
if  the  simple  pin  crown  is  to  be  used.  If  a  great  lateral  thrust 
from  mastication  is  to  be  expected,  the  retention  shown  in  Figs. 
199  and  202  should  be  used.  This  principle  also  apphes  to  an 
entire  gold  pin  crown  with  a  porcelain  facing,  but  as  the  method 
of  making  such  a  crown  is  so  weU  known,  further  explanation 
is  unnecessary. 

Amalgam  Crown  with  Porcelain  Facing. — Where  there  is 
little  or  no  lateral  stress,  as  in  the  case  of  a  bicuspid,  a  useful 
crown  can  be  made  not  only  easily  and  rapidly,  but,  above  all, 
free  from  gum  irritation  at  the  joint  of  union  with  the  root,  even 
though  the  root  is  very  frail  and  badly  broken  down.  The  root 
should  be  trimmed  so  that  the  labial  edge  is  well  below  the  gum. 
If  there  is  sufficient  root  to  permit  the  cutting  of  a  wedge  in  the 
head,  so  much  the  better.  The  head  of  the  root  is  first  pitted 
with  fine  undercuts,  and  a  countersimk  pinless  bicuspid  is  then 
ground  so  as  to  fit  well  under  the  gum  and,  at  the  same  time,  form 
a  good  articulation.  Undercuts  are  then  made  in  the  cavity  of 
the  tooth  with  a  diamond  disk  or  small  sharp  carborundum 
stones.  A  How  screw  post  is  then  inserted  and  cemented  into 
the  root  and  cut  off  just  long  enough  to  support  the  tooth  in 
proper  position.  The  tooth,  pin,  and  crown  are  then  joined  as 
follows:  The  cavity  of  the  tooth  is  filled  with  soft  amalgam; 
the  head  of  the  root  and  pin  are  covered  with  a  ball  of  soft  amal- 
gam; then  the  tooth  is  pressed  down  into  position  on  the  root  and 
pin  and  held  there  with  the  left  hand,  while  an  instrument  in  the 
right  hand  smoothes  the  soft  amalgam  into  partial  shape.    Then, 


268  MODERN  DENTISTRY 

still  holding  the  tooth  firmly  with  the  left  hand,  a  piece  of  sponge 
gold  should  be  pressed  against  the  lingual  surface  of  the  crown 
and  the  two  adjacent  teeth  in  such  a  way  as  not  to  interfere 
with  the  articulation.  The  gold  at  once  sucks  out  the  excess 
mercury  and  becomes  stiff  and  adherent  to  the  amalgam.  At 
the  end  of  five  minutes  the  patient  can  be  sent  away,  being  cau- 
tioned not  to  bite  upon  the  crown  for  twenty-four  hours.  When 
he  returns  on  a  later  visit  the  excess  amalgam  can  be  trimmed 
off  with  fissure  burs,  files,  and  sand-paper  strips.  This  method 
is  especially  valuable  for  roots  that  have  been  badly  broken 
down  through  decay,  as  the  metallic  salts  of  the  amalgam  filter 
through  the  weakened  root  material  and  seem  to  have  a  great 
preservative  power.  In  such  cases  it  is  particularly  essential 
that  the  occlusion  of  the  opposing  cusps  should  not  exert  ex- 
cessive lateral  stress. 

Inlay  Crowns. — ^This  type  of  crown  is  particularly  adapted 
to  the  restoration  of  molars,  and  may  be  used  with  or  without 
a  pin,  according  to  the  necessities  of  the  case.  The  inlay  crown 
reinforced  by  a  pin  will  be  described  first.  The  roof  of  the  pulp 
chamber  of  a  molar  into  which  the  inlay  is  to  project  is  usually 
just  level  with  the  gingival  margin  of  the  enamel.  The  head  of 
the  root  should  be  ground  smooth  and  flat.  In  this  procedure, 
however,  if  the  crown  of  the  natural  tooth  has  not  decayed 
to  the  gum  level  it  is  rather  an  advantage  that  the  tooth  margins 
should  extend  above  the  gum,  so  that  a  greater  tooth  cup  can  be 
obtained  for  purposes  of  retention.  The  pulp  chamber  and  the 
most  available  canal  should  be  enlarged  as  deeply  as  possible 
in  order  to  give  ample  room  for  the  pin  and  inlay.  It  is  wise 
to  trim  the  edges  of  the  cavity  in  the  crown  so  that  they  will 
come  to  the  margins,  as  in  Fig.  208,  not  as  in  Fig.  209,  as  much 
greater  stability  and  strength  is  obtained  by  avoiding  the  sharp 
angle  that  may  allow  the  porcelain  to  chip  under  the  stress  of 
mastication.  When  the  cavity  and  canal  have  been  prepared 
according  to  the  lines  described,  a  platinum  pin  should  be  inserted 
into  the  root  canal  as  far  as  possible.  The  pin  should  then  be 
removed  and  platinum  foil,  o.ooi  inch,  should  be  swaged  into 
position  with  bibulous  paper  and  burnished  with  steel  burnishers 


CROWNS 


269 


until  a  perfect  matrix  of  the  pulp  chamber  has  been  obtained. 
Then,  while  the  matrix  is  still  in  position,  the  pin  should  be 
punched  through  it  well  down  into  the  canal.  The  pui  and  foil 
should  then  be  fastened  together  with  hard  wax  and  should  then 
be  withdrawn  and  invested  with  a  mixture  of  half  plaster  and 
fire  clay.  The  investment  should  be  very  thin,  not  over  \  inch 
in  thickness.  Then  porcelain  of  the  desired  color  should  be  mixed 
to  the  proper  consistency,  as  described  in  Chapter  VIII,  and 
flowed  into  the  matrix  around  the  pin.  The  wax,  of  course, 
should  previously  have  been  picked  out  with  a  hot  instrument 
or  washed  out  with  hot  water.  In  applymg  the  first  portion  of 
porcelain  paste  care  should  be  taken  to  keep  the  edges  of  the 


Fig.  208. — Proper  way  of  sloping 
cavity  wall  in  a  root  for  an  inlay 
crown. 


Fig.  209. — Improper  way  of  trim- 
ming margins  of  cavity  in  root  where 
an  inlay  crown  is  to  be  used. 


platinum  matrix  free  from  the  paste  to  allow  of  a  further  adap- 
tation of  the  metal.  When  the  first  fusing  has  been  accomplished 
by  placing  the  invested  pin  and  matrix  in  the  furnace,  a  second 
application  of  porcelain  may  be  necessary  to  completely  fill  the 
mold  and  fuse  the  pin  firmly  into  position,  on  account  of  the 
shrinkage  of  the  first  supply  of  porcelain  body.  When  the  pin 
and  matrix  are  thoroughly  fused  together  in  proper  relationship 
by  the  porcelain,  the  investment  should  be  broken  away  and 
cleansed  from  the  pin  and  matrix,  and  the  fixture  placed  again 
in  position  in  the  mouth,  where  the  free  edges  of  the  matrix 
should  be  given  an  additional  burnish  to  secure  accurate  adap- 
tation. With  the  matrix  in  place  an  impression  should  be  taken 
of  the  adjacent  teeth.    Wax  should  then  be  flowed  over  the  pin 


270  MODERN  DENTISTRY 

and  under  side  of  the  matrix  to  permit  of  easy  removal;  and  a 
model  cast  with  the  pin  and  matrix  in  place.  When  the  model 
is  obtained  a  slight  amount  of  heat  applied  to  the  platinum 
matrix  and  pin  will  permit  of  easy  removal.  The  pin  can  be 
cut  off  to  the  proper  length  and  the  crown  built  up  according 
to  the  necessities  of  color  and  bite,  using  the  model  as  a  guide. 
Figures  210  and  211  show  the  finished  crown  and  the  outlines  of 
the  cavity  in  the  prepared  root.  Carved  crowns  are  frequently 
the  most  artistic  when  made  by  an  expert  porcelain  worker, 
but  ordinarily  the  dentist  will  get  the  best  results  by  making  use 
of  a  manufactured  facing  or  tooth  such  as  is  designed  for  vul- 
canite work.  The  tooth  can  be  selected  both  for  color  and  size, 
and  can  be  ground  and  fused  into  position  with  the  porcelain 


Fig.  210. — Inlay  crown  with  pin.  Fig.  211. — Inlay  crown  and  pin  in  posi- 

tion on  root. 


as  desired.  Before  the  edges  of  the  platinum  matrix  are  covered 
by  the  last  fusing  it  will  frequently  be  advisable  to  burnish  them 
finally  in  the  mouth  on  the  edges  of  the  root  to  ensure  perfect 
adaptation.  Before  the  tooth  is  set  the  platinum  matrix  should 
be  removed,  the  pin  roughened  and  the  cavity  undercut,  as 
previously  stated.  Above  every  other  consideration,  the  dowel 
principle  should  be  maintained  by  using  genuine  grooves  in  the 
tooth  cavity  that  is  to  hold  the  crown.  The  method  of  using 
silicious  cement  on  the  edges  and  phosphate  of  zinc  within  is 
also  advisable.  It  should  not  be  forgotten  that  the  chief  support 
of  this  crown  lies  not  in  the  pin,  but  in  the  inlay  of  porcelain 
that  fills  the  enlarged  pulp  chamber.  If  two  pins  are  deemed 
advisable,  they  can  be  used  if  they  are  not  too  long,  and  if  the 


CROWNS  271 

pulpal  openings  of  the  canals  are  sufficiently  enlarged  to  make  it 
possible  to  overcome  the  divergence  of  the  canals.  If  it  is  desired 
to  make  these  molar  crowns  without  the  use  of  a  model  the  fol- 
lowing method  can  be  employed,  and,  as  a  matter  of  fact,  an 
experienced  porcelain  worker  seldom  uses  a  model.  When  the 
matrix  and  pin  are  stiffened  with  porcelain,  as  herein  described, 
a  countersunk  tooth,  such  as  is  used  for  vulcanite  work,  of  the 
proper  size  and  color,  may  be  roughly  ground  to  fit  the  head  of 
the  root  and  bite.  The  pins  of  the  tooth  should  be  cut  away  and 
the  countersunk  portion  filled  with  porcelain  paste.  The  tooth 
can  then  be  placed  in  its  proper  position 
on  the  platinum  matrix  and  fused,  care  r^     N^       A 

being  taken,  as  before  stated,  to  leave  W "n 

the  platinum  edges  free  for  final  burn-        — A  "' f 

ishing  and  finishing.     Instead  of  using  y        1 

a    manufactured    tooth,    however,    the  /      /\       I 

experienced   worker  will   usually  build  /    /  / 

the  tooth  up  with  porcelain,  molding  [y         [y 

it  into  shape  where  necessary,  and  carv-       p.-     212.— Simple  inlay 
ing  it  after  the  final  fusing  to  give  the  crown. 

proper  bite  and  contour. 

As  before  stated,  with  an  inlay  crown  the  mass  of  porcelain 
within  the  cavity  is  the  chief  source  of  retention,  and,  therefore, 
it  is  sometimes  difficult  to  know  whether  one  is  inserting  an  inlay 
or  crown.  For  instance,  in  a  case  such  as  is  shown  in  Fig.  212, 
is  it  an  inlay  or  a  crown  that  is  required?  The  broken  tooth  has 
left  a  little  more  than  a  third  of  the  natural  crown.  The  dotted 
line  shows  the  size  of  the  inlay  and  its  outline.  Before  the  days 
of  insoluble,  invisible  silicious  cements  such  a  tooth  would  ordi- 
narily have  been  cut  down  to  the  gum  margins  to  conceal  from 
the  patient's  eye,  and  perhaps  the  shrinking  eye  of  the  dentist, 
the  unsightly  edge  that  was  sure  to  appear  in  the  course  of  a 
year  or  two;  but  now,  with  the  aid  of  these  cements,  no  such 
fear  need  restrain  us  from  putting  our  edges  boldly  above  the 
gum,  knowing  that  a  moderate  amount  of  skill,  and  an  eye 
fairly  exact  in  the  selection  of  colors,  will  enable  the  operator  to 
make  a  cleanly,  inconspicuous  operation.     A  porcelain  filling 


272 


MODERN  DENTISTRY 


ought  to  be  inconspicuous  at  the  distance  of  6  inches,  and,  as  a 
bright  girl  once  said,  "If  anyone  gets  closer  than  that  he  won't 
see  it  anyway."  If  the  sides  of  the  tooth  are  decayed  well  down 
to  the  gum  on  all  sides,  the  pin  is  an  advantage,  but  if  the  tooth 
is  only  partly  gone,  the  porcelain  crown  or  inlay,  as  just  described, 
can  be  made  without  the  pm,  the  deep,  sloping  cavity  walls 
being  a  sufficient  source  of  retention. 

When  there  is  unusual  stress  in  mastication,  and  the  color  of 
the  filling  is  not  an  objection,  the  gold  inlay  or  crown  can  be 
quickly  and  readily  made  by  a  modification  of  the  method 
just  described.  The  cavity  in  the  tooth  is  prepared  as  in  Figs. 
211  and  212,  and  gold,  0.003  inch,  is  used  for  the  matrix  instead 
of  platinum.  While  the  matrix  is  in  position  the  pin  is  punched 
through  it  into  the  root  canal  and  the  cavity  packed  with  sponge 
gold  until  the  matrix  and  pin  are  firmly  joined  together.  The 
matrix  and  pin  should  then  be  teased  out  by  gently  raising 
the  sides  of  the  matrix,  first  on  one  edge  and  then  on  the  other. 
When  it  has  been  removed  the  pin  can  be  seized  with  a  pair  of 
pliers  and  22-karat  solder  can  be  flowed  into  the  sponge  gold. 
Then  the  fiUed  matrix  and  pin  can  be  replaced  in  position  and  the 
edges  burnished,  when  more  sponge  gold  can  be  added  and  more 
solder  used  until  the  complete  gold  crown  has  been  made;  or, 
if  desired,  a  porcelain  top  can  be  adjusted  in  any  one  of  the 
numerous  ways  known  to  the  mechanical  dentist. 

The  Band  Crown. — We  now  come  to  the  band  crown — the 
malefactor — and  yet  in  many  instances  the  only  resource.  For, 
as  before  stated,  when  it  extends  below  the  gum  its  benefit  is 
problematic,  but  when  its  edge  is  at  or  above  the  gum  margins 
it  is  a  tower  of  strength  and  stabihty.  For  instance,  take  the 
case  of  a.  superior  upper  incisor  that  has  lost  its  pulp  and  has 
been  so  seriously  discolored  that  its  appearance  is  hopelessly 
ruined,  while  its  intrinsic  stability  is  so  undermined  by  decay 
that  a  pin  crown  would  be  ill-advised.  In  such  a  case  the  band 
crown  is  called  for  (Fig.  213).  The  cementum  is  the  healthiest 
structure  of  the  whole  tooth,  and  the  only  possible  means  of 
preserving  the  root  is  to  fill  it  up  boldly  and  then  to  band  it. 
The  first  essential,  of  course,  must  be  perfect  sterilization  and 


CROWNS 


273 


cleansing  of  the  root  canal,  followed  by  careful  sealing  of  the  tip 
with  gutta-percha.  When  this  has  been  accomplished,  as  de- 
scribed in  Chapter  VI,  the  entire  interior  of  the  root  and  tooth 
should  be  filled  with  amalgam.  In  cases  where  decay  has  pro- 
gressed to  a  very  extensive  degree  a  How  screw  may  be  inserted 
in  the  canal  and  the  amalgam  packed  around  it  and  the  excess 
mercury  extracted  with  sponge  gold.  The  amalgam  is  useful 
in  arresting  decay  by  the  infiltration  of  its  salts  into  the  tooth 
substance,  although  it  sometimes  has  also  an  unfortunate  ten- 
dency to  turn  the  root  black,  so  that  any  portion  of  root  appear- 
ing above  the  gum  is  conspicuous.  When,  therefore,  the  weak- 
ened tooth  or  root  has  been  properly  sterilized  and  filled,  as  just 


Fig.    213. — Broken-down    central    in- 
cisor root  to  be  banded  and  crowned. 


Fig.  214. — Broken-down  incisor 
root  built  up  with  a  screw  and  amalgam 
ready  for  banding. 


described,  it  must  be  shaped  at  the  gum  margin  with  slightly 
conical  sides,  as  shown  in  Fig.  214.  A  bevel  edge  0.05  inch  in 
extent  is  ample  retention  for  a  crown  if  the  band  fits  accurately 
and  is  rigid  enough  to  withstand  the  stretching  force  of  masti- 
cation. When  platinum  or  gold  is  used  No.  30  B.  &  S.  gage  is 
strong  enough  for  a  band  that  averages  -g-  inch  in  diameter. 
All  bands  exceeding  that  size  should  be  No.  29  gage,  which 
thickness  will  be  strong  enough  to  give  stability  to  any  crown. 
The  great  advantage  of  a  simple  crown  band  on  a  0.05  inch  bevel 
lies  in  the  fact  that  if  at  any  time  the  porcelain  facing  chips  or 
spKnters  away  and  requires  repairing,  a  strong  pull  away  from 
the  gum  fine  with  a  heavy  enamel  scaler  will  easily  dislodge  it. 


274 


MODERN  DENTISTRY 


and  make  the  repair  simple  for  the  dentist  and  of  great  ease  for 
the  patient.  Where  this  procedure  is  not  feasible,  through  a 
too  great  adherence  of  the  cement,  a  small  cut  in  the  edge  of  the 
band  will  make  its  removal  easy,  and  the  cut  in  the  band  can  be 
readily  soldered  before  the  tooth  is  finally  repaired.  The  direct 
tension  away  from  the  root  is  never  exerted  in  the  act  of  masti- 
cation, and  therefore  such  a  possibility  of  easy  removal  does  not 
mean  that  the  band  crown  will  not  be  amply  able  to  withstand  the 
stress  of  chewing  without  being  dislodged.  Unfortunately,  how- 
ever, there  is  no  operation  that  has  not  its  percentage  of  failures, 
but  it  can  be  safely  said  that  if  a  band  accurately  fits  a  slightly 
conical  head  of  a  root,  and  is  cemented  on  with  proper  regard 
for  the  dowel  action  of  the  cement  and  care  as  to  dryness,  there 


@ 


Fig.  215. — Head  of  instru-  Fig.   216. — Instrument  with  wire  loop  in- 

ment  to  receive  wire  loop  for  serted   ready   to   be  slipped   around   head  of 

measuring     circumference     of  root, 
root  prepared  for  banding. 

is  no  reason  why  the  crown  should  not  remain  firmly  attached. 
The  failures  usually  arise  from  the  fact  that  the  band  does 
not  quite  fit,  or  that  it  is  too  thin  and  stretches,  or  that  the 
cement  is  not  properly  mixed,  or  last,  and  most  frequently, 
moisture  creeps  in  between  the  root  and  cement  while  the  crown 
is  being  set  in  position. 

The  first  band  crown  that  will  be  described  is  the  crown 
consisting  of  a  platinum  band  for  a  base,  with  a  covering  of 
porcelain  built  and  baked  upon  it.  The  method  of  procedure 
is  extremely  simple  when  the  art  of  mixing  and  baking  porcelain 
is  mastered.  Take,  for  example,  the  construction  of  an  upper 
incisor,  as  shown  in  Fig.  214.  The  figure  represents  the  frontal 
aspect  of  a  broken-down  upper  central  incisor,  where  the  root 
canal  has  been  filled  and  the  conical  top  of  the  root  has  been 


CROWNS 


275 


prepared.  A  represents  a  screw  which  has  been  inserted  into 
the  root,  B  the  amalgam  which  has  been  packed  into  root  and 
around  the  screw,  C  the  projecting  stump  composed  of  amalgam 
and  root,  D  the  adjacent  upper  central  incisor,  and  E  the  adja- 
cent upper  lateral  incisor.  The  measure  of  the  base  of  the  cone 
is  taken  with  No.  30  brass  wire  as  follows:    Figure  216  represents 


:^sdKO 


Fig.  217. — Wire  loop  drawn  tight  and  removed  from  head  of  root. 

a  steel  rod  with  two  holes  drilled  from  the  opposite  sides  to  a 
common  orifice  in  the  end  (Fig.  215).  The  wire  is  passed  through 
these  holes,  forming  a  loop.  When  this  has  been  accomplished 
the  loop  is  passed  around  the  root  near  the  gum,  and  the  loose 
ends  drawn  upon  it  until  the  loop  approximately  encircles  and 
fits  the  root.  Then  the  rod  is  slowly  revolved  until  a  closely 
fitting  wire  ring  fastened  by  a  couple  of  twists  is  the  result.    The 


-^Kiy 


Fig.  218. — ^Loop  split  and  straightened 
to  show  length  metal  should  be  cut  to  form 
band. 


Fig.  219. — Platinum  band  fitted 
to  root  preparatory  to  making 
porcelain  crown. 


loop  is  then  slipped  off  the  root,  cut  with  a  pair  of  scissors  and 
straightened  out,  so  that  it  resembles  Fig.  218  and  gives  the  exact 
size  of  the  circumference  of  the  band  to  be  used.  The  strip  of 
platinum  for  the  band  should  then  be  cut  either  of  No.  30  or  No. 
29  gage,  according  to  the  size  of  the  root,  and  of  a  width  a  httle 
less  than  the  entire  length  that  the  finished  tooth  is  to  possess. 


276 


MODERN  DENTISTRY 


The  band  should  be  made  0.02  inch  shorter  than  the  wire.  The 
ends  of  the  piece  of  cut  platinum  should  now  be  brought  together 
with  a  slight  lap,  soldered  with  pure  gold  and  hammered  so  that 
the  soldered  ends  will  be  even  and  level  with  the  rest  of  the  band. 
The  band  is  now  ready  for  adjustment  to  the  root.  The  band 
should  now  be  pressed  upon  the  root,  jamming  and  stretching 
it  upon  the  cone  until  it  fits  the  root  evenly  all  around,  and  touches 
the  gum  but  does  not  impinge  or  go  under  it.  When  the  band 
is  being  fitted  it  should  be  cut  away  with  an  engine  stone  where 
it  impinges  so  that  it  will  finally  fit  without  lacerating  the  tissues. 
At  this  point  it  resembles  Fig.  219.  The  band  should  then  be 
compressed  near  the  cutting  edge  until  it  fills  up  the  space  the 


Fig.  220. — Band  compressed  at 
cutting  edge  to  fill  space  between 
teeth. 


Fig.  221. — Platirium  band  trimmed 
labially  preparatory  to  final  shaping  to 
receive  porcelain  finish. 


finished  tooth  is  to  occupy,  as  in  Fig.  220.  Then  a  curved  piece 
of  platinum  is  cut  out  of  the  labial  side,  as  in  Fig.  221,  and  a 
cut  made  in  the  labial  portion  that  is  left,  that  will  reach  to  the 
top  of  the  root.  When  this  has  been  done  the  platinum  on  the 
labial  side  should  be  boldly  pressed  down  over  the  head  of  the 
root,  and  ground  and  molded  so  as  to  form  a  complete  skeleton 
cap  that  will  firmly  fit  the  root  and  occluding  bite,  and  yet  will 
allow  ample  space  for  the  porcelain  that  is  now  to  be  added, 
according  to  the  color  and  size  desired.  The  side  view  of  the 
cap  is  now  as  seen  in  Fig.  222.  The  cap  is  now  removed  and  is 
ready  for  the  porcelain,  that  should  be  added  as  described  in 
Chapter  VII,  until  it  res{;mbles  Fig.  223.     The  dotted  hues  A 


CROWNS  277 

show  the  porcelain  that  enters  within  the  body  of  the  cap  for 
purposes  of  retention ;  B  represents  the  porcelain  face  of  the  tooth 
when  the  process  is  completed.  When  the  platinum  cap  has  been 
made,  its  completion  with  the  porcelain  bodies  is  extremely 
simple  and  easy.  The  color  in  the  shade  guide  should  be  chosen ; 
the  mixture  made  according  to  the  formula,  care  being  taken  in 
this  work  to  add  a  little  extra  yellow  to  counteract  the  blue  of 
the  underlying  platinum.  The  first  baking  should  be  made 
from  the  tip  down  to  the  hollowed-out  portion  of  the  cap.  The 
second  and  third  bakings  should  cover  the  entire  anterior  surface 
of  the  completed  tooth.  In  the  last  baking,  where  the  shghtest 
excess  of  baking  would  cause  the  platinum  underneath  to  show 


Fig.  222. — Cross-section  side  view        Fig.    223. — Porcelain    central    incisor 
of    platinum    cap    ready    to    receive  with  platinum  base, 

porcelain  covering. 

through  and  spoil  the  color,  it  is  wise  to  bake  very  slowly  and  to 
stop  while  the  final  surface  is  still  slightly  granular.  This  can 
readily  be  gone  over  with  a  sand-paper  disk,  and  the  porcelain 
will  take  a  beautiful  polish,  and  yet  will  prevent  the  blue  color 
of  the  platinum  beneath  from  showing  through.  As  before 
stated,  care  should  be  taken  to  see  that  the  band  crown  is  set 
with  great  care  as  to  dryness  and  regard  for  the  dowel  effect 
of  the  cement.  Sometimes  if  the  band  cannot  readily  reach 
the  labial  aspect  of  the  gum,  and  the  fine  of  the  band  and  root 
is  disconcertingly  evident,  it  is  good  practice  to  cut  this  line 
out  with  a  fissure  bur  or  inverted  cone  bur,  and  fill  in  the  space 
with  a  well-chosen  silicious  cement  that  will  completely  conceal 


278 


MODERN  DENTISTRY 


the  edge  of  the  rim  and  make  a  smooth,  even  contour  with  the 
root  and  the  crown. 

In  making  a  bicuspid  or  molar  the  same  principle  and  pro- 
cedure hold,  with  a  few  necessary,  slight  modifications.    In  either 


Fig.    224. — Bicuspid   prepared   to 
receive  platinum  band  for  porcelain 


Fig.  225. — Side  view  of  platinum  shell 
and  band  for  porcelain  bicuspid. 


case  the  head  of  the  root  should  be  trimmed  to  a  cone,  as  pre- 
viously described,  care  being  taken  not  to  allow  the  band  to 
extend  beyond  the  bevel  of  the  root  into  the  gum.  The  width 
of  the  band  should  not  come  up  to  the  occluding  tooth  and  should 


Fig.  226. — Platinum  shell  and  band  for  porcelain  crown  in  its  relation  to  adjacent 

teeth. 

be  short  enough  to  allow  a  generous  covering  of  porcelain.  The 
greater  the  body  of  porcelain,  the  less  likelihood  is  there  of  frac- 
ture from  mastication.  For  instance,  Fig.  224  represents  a  bicus- 
pid root  that  has  been  prepared  for  a  platinum  band  filled  with 


CROWNS 


279 


porcelain.  Figure  225  represents  the  three-quarter  aspect 
showing  the  band  in  position.  A  shows  flap  of  platinum  bent  over 
on  the  head  of  the  root  C  to  form  a  partial  cup  to  receive  the 
porcelain,  B  shows  sides  of  the  band.  Figure  226  shows  the 
buccal  aspect  of  the  same  crown  and  band.  B  represents  the 
upper  part  of  the  band  with  the  edges  spread  so  as  to  make  good 
approximal  contact  with  the  adjacent  tooth,  C  represents  the 
exposed  root,  and  A  the  flap  turned  in  to  make  the  cup  for  the 
porcelain.  The  method  of  procedure  in  applying  the  porcelain 
is  exactly  the  same  as  with  the  central  incisor,  previously  de- 
scribed.    However,  with  the  bicuspids  and  molars  great  care 


Fig.  227. — Molar  root  trimmed 
for  adjustment  of  gold  crown  with  a 
porcelain  face. 


Fig.  228. — Gold  band  in  position. 
Dotted  line  shows  the  head  of  the  root. 
Band  should  be  cut  off  at  this  line  and 
a  top  adjusted. 


must  be  taken  with  the  grindmg  surface  to  reproduce  the  cusps 
and  contours. 

If  it  is  desired  to  make  a  gold  cap  with  a  porcelain  facing 
the  procedure  is  obvious  to  those  who  know  the  ordmary  proc- 
esses of  crown  and  bridge  work.  Yet  it  might  not  be  out  of 
place  to  briefly  describe  one  of  the  simpler  methods.  Let  us 
take,  for  example,  a  molar  root  that  has  been  prepared  for  the 
crown,  as  in  Fig.  227.  The  band  is  prepared  of  No.  29  gage 
gold  plate  composed  of  22  parts  gold,  i  of  copper,  and  i  of  silver. 
The  root  with  the  band  in  position  appears  as  in  Fig.  228.  The 
dotted  line  represents  the  position  of  the  top  of  the  root.  The 
band  is  now  ground  level  with  the  root  top  while  it  is  in  position; 
it  is  then  removed  and  a  piece  of  pure  gold  plate.  No.  30,  is  sol- 


28o 


MODERN  DENTISTRY 


dered  on  top  with  2  2 -karat  solder,  trimmed  evenly,  and  polished. 
When  the  cap  is  replaced  in  position  the  pure  gold  can  be  bur- 
nished and  worked  with  broad-faced  pluggers  until  it  absolutely 
fits  the  upper  surface  of  the  root.  Then,  as  is  shown  in  Fig.  229,  a 
porcelain  facing,  B,  with  platinum  pins  is  ground  to  fit  the  buccal 
edge  of  the  cap  A.  The  facing  is  backed  with  pure  gold  and 
fastened  to  the  cap  with  hard  wax,  C.  The  bite  is  contoured 
in  wax  and  reproduced  in  gold  in  any  of  the  numerous  ways 
commonly  known.  When  a  complete  gold  sheU  is  desired,  and 
the  question  of  color  is  of  no  consequence,  the  making  of  a  gold 
crown  is  a  question  of  a  few  minutes  from  the  time  the  root  has 
been  properly  filled  and  prepared.    Let  Fig.  230  represent  such 


Fig.  229. — Ordinary  porce- 
lain-faced gold  band  crown 
properly  adjusted  to  root. 


Fig.  230. — Root  trimmed  for  adjustment  of  gold 
shell  crown. 


a  molar  root.  The  band  should  be  made  of  No.  29  gage  gold 
plate,  as  previously  described.  The  proper  measurement  should 
be  made  with  a  brass  wire  and  the  band  cut  0.02  inch  short. 
The  ends  of  the  band  should  then  be  brought  together  with  a 
slight  lap,  powdered  borax  placed  upon  the  Kne  of  juncture, 
and  the  band  held  in  a  Bunsen  burner  until  the  two  ends  are 
sweated  together.  The  joint  should  then  be  hammered  even, 
and  we  have  a  seamless  collar  the  right  size  for  the  work.  This 
should  then  be  pressed  down  upon  the  root  and  fitted  to  the  gum, 
as  just  described.  The  occlusal  edge  should  also  be  ground  so 
as  just  to  miss  the  opposing  teeth,  the  sides  also  should  be  bulged 
and  jammed  out  so  that  they  make  proper  contact  with  the 


CROWNS 


adjacent  teeth  and  protect  the  approximal  space  on  each  side. 
Then  we  have  the  band  assuming  a  position  such  as  is  shown  in 
Fig.  231.  When  this  has  been  accomplished  a  suitable  mold 
is  chosen  from  a  die  plate  containing  inlay  impressions  of  tooth 
cusps.  A  top  for  the  crown  is  swaged  of  pure  gold  No.  30  B.  &  S. 
gage.  This  top  is  then  fitted  approximately  to  the  band  and 
tacked  into  position  on  four  sides  with  22-karat  solder,  care 
being  taken  that  it  is  sufficiently  high  to  reach  the  occluding 
tooth  and  that  the  solder  used  for  tacking  it  into  position  does 
not  get  upon  the  gold  cusps,  rendering  them  stiff  and  rigid. 
When  this  has  been  done  the 
crown  is  filled  with  soft  wax  and 
placed  in  position  on  the  root. 
The  patient  is  then  told  to  sink 
his  teeth  into  it  and  to  swing  the 
jaw  so  as  to  get  a  perfect  plane 
of  mastication.  The  soft  gold 
yields  to  the  pressure  and  per- 
fectly occluding  cusps  are  quickly 
formed.  If  the  gold  is  driven 
down  too  far  it  must  be  raised  in 
that  particular  spot  by  a  broad- 
faced  plugger.  So  far  the  crown 
consists  of  a  well-fitting  band 
and  perfectly  occluding  cusps 
made  in  thin  gold.  It  is  taken  off 
the  root,  the  wax  removed,  and 
sponge  gold  packed  into  the 
inside  of  the  crown  next  to  the  grinding  surface,  so  that  it  makes 
the  grinding  surface  at  least  T2  inch  in  thickness.  This  can 
can  readily  be  done  without  distorting  the  soft  gold  face.  Pow- 
dered borax  can  now  be  sprinkled  within  the  gold  cap,  pieces  of 
22-karat  solder  added,  and  the  whole  appHance  held  in  a  Bunsen 
burner  until  the  interstices  of  the  sponge  gold  are  filled.  This 
crown  can  then  be  polished  and  set  in  position  in  the  usual  way, 
care  being  taken  not  to  polish  the  side  so  as  to  destroy  the  firm 
union  of  the  crown  with  the  contact  points  of  the  adjacent  teeth. 


Fig.  231. — Gold  band  adjusted  to 
root  and  adjacent  teeth  ready  for  soft 
gold  top,  into  which  the  occluding 
teeth  are  to  be  bitten  to  make  a  per- 
fect and  easily  adapted  bite. 


CHAPTER  X 
THE  REPLACING   OF  LOST  TEETH 

The  Attached  Bridge.     The  Removable  Bridge. 

The  Attached  Bridge. — As  has  previously  been  stated,  a 
bridge  that  cannot  be  kept  clean  should  never  be  placed  in  the 
mouth.  Many  pieces  of  removable  bridge  work  attached  by 
telescope  crowns  are  so  bulky  and  badly  constructed  at  the  gum 
margin  that  although  the  bridge  itself  can  be  cleansed,  never- 
theless the  inner  crowns,  by  their  impingement  on  the  gum 
tissues,  are  a  constant  menace  to  the  health  of  the  mouth  tissues 
and  a  possible  source  of  general  infection  throughout  the  body. 
On  general  principles,  therefore,  the  simplest  appliances  consist- 
ent with  strength  and  durability  are  to  be  preferred. 

The  replacement  of  a  single  incisor  or  canine,  where  the  teeth 
on  both  sides  are  normal  and  sound,  has  been  considered  the 
bete  noire  of  dentistry.  It  has  generally  been  associated  with 
extensive  banding  and  crowning  of  one  or  both  adjacent  teeth, 
and  only  too  frequently  the  procedure  has  been  followed  by 
inflammation  and  infection  of  the  gums  around  the  abutments. 
As  a  matter  of  fact,  there  need  be  no  difi&culty  in  making  a  useful, 
permanent,  natural,  and  cleanly  fixture  for  the  replacement  of 
such  a  tooth.  Take,  for  instance,  the  restoration  of  an  upper 
central  incisor  where  the  other  central  and  the  adjacent  lateral 
incisors  are  normal.  The  procedure  is  as  follows:  The  pulp  in 
one  tooth  is  removed,  the  canal  tip  filled  as  described  in  Chapter 
VI.  Then  the  canal  is  reamed  out  and  a  piece  of  iridioplatinum 
or  platinized  gold  wire.  No.  14  or  16  B.  &  S.  gage,  is  inserted 
in  the  canal  as  far  as  possible.  The  wire  is  then  bent  at  right 
angles  across  the  space  and  the  end  fitted  into  a  shallow  groove 
that  has  been  made  in  the  lingualaspect  of  the  other   tooth. 


THE  REPLACING  OF  LOST  TEETH 


283 


The  wire  abutment  must  be  set  so  as  to  avoid  the  bite  of  the 
occluding  lower  teeth.  A  porcelain  dummy  that  fits  the  gum 
and  has  a  suitable  color  is  then  soldered  to  the  bar  in  the  usual 
way,  and  the  whole  appliance  is  cemented  into  position,  one  side 
being  attached  and  the  other  free.  In  this  way  it  is  possible 
for  the  fioss-silk  to  be  passed  under  the  loose  end  of  the  bar, 
insuring  perfect  cleanliness.  It  is  essential  to  carve  the  porce- 
lain dummy  so  that  it  will  conform  to  the  characteristics  of  the 
adjacent  teeth,  as  shape  is  even  more  important  as  a  means  of 
concealment  than  color.  In  cementing  the  appliance  into  place 
the  lower  portion  of  the  canal  should  be  filled  with  phosphate 
cement,  and  silicious  cement  should  be  placed  around  the  pin 


Fig.  232. — Missing  upper  central 
incisor.  Ordinarily  considered  most 
difficult  to  replace. 


Fig.  233. — Preparation  of  teeth 
for  replacement  of  missing  upper  cen- 
tral incisor. 


where  it  emerges  from  the  tooth.  The  appliance  when  set  will 
thus  have  an  adhesive  cement  holding  the  pin  in  the  tooth,  while 
the  insoluble  silicious  cement  wiU  seal  the  orifice  of  the  canal 
around  the  pin. 

The  procedure  is  shown  as  follows:  Let  Fig.  232  represent  the 
lingual  aspect  of  the  case  in  question.  Figure  233  represents 
the  central  incisor  opened  up,  its  pulp  removed,  and  the  pulp 
chamber  sterilized  and  filled  at  the  tip,  and  with  a  groove  in  the 
enamel  running  off  the  orifice  of  the  pulp  canal  to  receive  the 
platinum  bar  as  it  spans  the  space  between  the  two  teeth.  The 
end  of  the  bar  rests  in  the  shallow  groove  shown  in  the  lingual 
face  of  the  lateral  incisor.    Figure  234  shows  the  bar  in  position, 


284  MODERN  DENTISTRY 

and  the  facing  ground  and  backed  with  pure  gold  ready  to  be 
fastened  on  the  bar  with  hard  wax,  so  that  the  appliance  can  be 
removed  and  soldered.  Figure  235  represents  the  finished  ap- 
pliance ready  for  setting  with  cement.  The  curved  lines  repre- 
sent the  solder  which  gives  the  Hngual  contour  and  unites  the  bar 
firmly  to  the  tooth.  As  the  tendency  of  the  bite  of  the  lower 
teeth  is  to  keep  the  loose  end  of  the  bar  in  its  position  in  the 
groove,  this  appliance  usually  gives  perfect  satisfaction.  And  as 
the  floss-silk  can  be  passed  between  the  pin  and  the  lateral  in- 
cisor, and  under  the  fixture  across  the  gum,  there  is  no  difiiculty 
in  keeping  such  an  appliance  as  clean  as  a  natural  tooth.  The 
groove  in  the  lateral  incisor  that  receives  the  bar  usually  does 


Fig.  234. — Lingual  view  of  assem-        Fig.  235. — Bridge  to  replace  lost  upper 
bled  bridge  to  replace  lost  upper  cen-  central  incisor, 

tral  incisor. 

not  go  completely  through  the  enamel,  but  if  it  does,  a  shallow 
inlay  of  gold  can  be  inserted  containing  a  groove;  or  the  cavity  can 
be  undercut  and  filled  with  insoluble  siHcious  cement,  in  which 
the  groove  for  the  tip  of  the  bar  can  be  made.  In  any  case  there 
will  be  no  tendency  for  decay  to  start  under  the  bar  if  the  sur- 
face is  swept  daily  with  floss-silk.  In  fact,  enamel  will  not  be 
decayed  by  any  colony  of  bacteria  that  is  less  than  a  day  old. 
Decay  results  because  the  colony  is  not  removed  daily,  and  usually 
remains  undisturbed  week  in  and  week  out.  Decay  is  primarily 
the  result  of  undisturbed  filth,  and  if  the  refined  members  of 
society  would  be  one-quarter  as  careful  of  the  cleanliness  of  their 
mouths  as  they  are  of  keeping  their  persons  clean,  decay  of  their 
teeth  would  soon  be  unknown. 


THE  REPLACING  OF  LOST  TEETH  285 

The  next  bridge  described  will  be  the  restoration  of  a  missing 
bicuspid  or  molar  by  an  immovably  attached  fixture,  where  the 
teeth  on  both  sides  are  sound.    This  is  the  inlay  cantilever  bridge, 
that  depends  upon  a  gold  inlay  and  pin  inserted  into  the  pulp 
chamber  as  a  means  of  retention.     Instead  of  demanding  the 
removal  of  all  the  enamel  from  the  abutment  the  construction 
demands  the  preservation  of  the  enamel  for  its  strengthening 
quality  and  its  beauty  of  appearance.    If  the  pulp  has  previously 
been  destroyed  and  the  canals  filled  aseptically,  so  much  the 
better.    Described  in  a  few  words,  the  bridge  consists  of  a  gold 
inlay  through  which  a  bar  projects  into  the  root  canal  of  the 
abutment  tooth,  which  bar  also  extends  across  the  gap  to  a 
groove  on  the  edge  of  the  occlusal  surface  of  the  other  abutment. 
The  porcelain  facing  or  dummy  is  soldered  to  this  bar.    In  fact, 
this  bridge  is  similar  in  principle  to  the  incisor  bridge  just  de- 
scribed, except  that  the  broad  masticating  surface  of  the  dummy 
gives  a  tipping  tendency,  which  is  overcome  by  making  the  gold 
inlay  extend  into  and  over  the  grinding  surface  of  the  stationary 
abutment.    If  there  is  a  filHng  in  the  approximal  grinding  surface 
of  the  molar  that  is  to  act  as  an  abutment  so  much  the  better; 
if  not,  a  cavity  should  be  cut  out  sufficiently  large,  but  not  large 
enough  to  let  the  gold  obviously  show  when  the  bridge  is  cemented 
into  position.    The  cavity  should  extend  well  toward  the  gum 
line  if  the  tooth  is  perfectly  sound ;  and  if  the  enamel  at  the  base 
of  the  cavity  seems  at  all  infected  it  is  better  to  let  the  cavity 
extend  to  the  cementum.    Then,  when  the  cavity  has  been  pre- 
pared with  straight,  slightly  sloping  sides.  No.  14  platinum  wire 
should  be  filed  to  a  suitable  point  and  fitted  as  deeply  as  pos- 
sible into  the  most  available  root  canal  of  the  molar,  the  canal 
having  been  previously  prepared  to  receive  it.    Then  the  wire 
should  be  bent  to  extend  across  to  the  face  of  the  first  bicuspid, 
where  a  convenient  groove  has  been  prepared,  such  as  has  been 
previously  described.    For  instance,  Fig.  236  represents  the  side 
view  of  the  molar  with  the  outhne  of  cavity  shown  in  dotted 
lines,  and  with  the  platinum  or  gold  bar  extending  across  the 
space  to  be  bridged.    Figure  237  shows  the  full  occlusal  view, 
A  showing  the  grinding  surface  of  the  bicuspid,  B  the  grinding 


286  MODERN  DENTISTRY 

surface  of  the  molar,  with  outlined  cavity  containing  the  bar 
that  projects  across  the  space  to  be  bridged,  and  rests  in  the 
groove  on  the  occlusal  surface  of  the  bicuspid.  This  groove 
ordinarily  should  not  be  made  deeper  than  one-half  the  thickness 
of  the  enamel. 


Fig.  236. — Pin  and  bar  in  position  for  attachment  of  a  bicuspid  dummy. 

When  the  bar  has  been  accurately  adjusted  and  removed, 
gold  foil  0.003  inch  in  thickness  should  be  burnished  into  the 
cavity  of  the  molar  until  a  perfect  matrix  is  formed — if  the  bot- 
tom of  the  matrix  is  punched  through  it  is  of  small  consequence. 
When  the  matrix  is  completed  and  in  position,  the  pointed 
platinum  wire  should  be  punched  through  the  bottom  of  the 


Fig.  237. — Occlusal  view  of  bar  in  position  running  into  lingual  root  of  molar. 
Dummy  with  a  porcelain  face  is  to  be  soldered  to  the  bar  to  replace  lost  bicus- 
pid. 

matrix  into  the  root  canal  prepared  for  it,  and  the  extension 
fitted  accurately  into  position  in  the  groove  of  the  bicuspid. 
When  this  has  been  done,  sponge  gold  should  be  firmly  packed 
into  the  matrix  around  the  bar,  building  it  almost  up  to  the 
matrix  edges.  If  a  little  moisture  gets  into  the  matrix  it  does  not, 
of  necessity,  interfere  with  the  operation.    When  the  gold  is  hard 


THE  REPLACING  OP  LOST  TEETH  287 

and  condensed  the  entire  piece  may  be  removed  by  grasping 
the  cross-bar  with  a  pair  of  pliers,  and  then  the  matrix,  sponge 
gold,  and  bar  can  be  readily  soldered  together  with  borax  and  22- 
karat  solder.  This  can  easily  be  done,  without  investment,  in 
an  ordinary  Bunsen  burner,  the  only  care  required  being  that  the 
solder  should  be  placed  upon  the  sponge  gold  and  not  allowed 
to  flow  upon  the  outside  surface  of  the  matrix,  for  such  an  acci- 
dent will  prevent  the  inlay  from  fitting  accurately.  When  the 
piece  is  cold  it  should  be  replaced  in  the  cavity  and  the  entire 
matrix  edges  burnished  to  position,  and  the  bar  bent  back  into 


Fig.  238. — Cantilever  bridge  with  porcelain  side  and  grinding  surface  designed 
to  replace  lost  bicuspid.  Attachment  is  made  to  bicuspid  by  pin  A  and  gold  inlay 
B.  A  pin  in  gold  cup  C  holds  the  porcelain  tooth  firmly  when  cemented  into 
position,  and  the  spud  D  rests  upon  the  molar,  giving  firm  support  on  the  unfas- 
tened side  of  bridge.  The  figure  on  the  right  represents  the  under  side  of  the 
porcelain  tooth  with  the  hole  for  the  pin. 

its  proper  place,  if  it  has  been  slightly  distorted  during  the  first 
removal.  More  sponge  gold  and  solder  can  now  be  added  until 
the  inlay  has  the  proper  occlusion.  After  the  second  soldering 
the  inlay  should  be  placed  in  position,  and  the  porcelain  dummy 
ground,  adjusted,  and  waxed  into  position.  The  fixture  can  then 
be  removed  and  the  dummy  soldered  to  the  pin  and  inlay.  The 
bridge  is  then  ready  to  be  cemented  into  place.  If  it  is  a  lower 
molar  that  is  to  be  used  for  an  abutment,  the  posterior  canal 
should  be  used  to  receive  the  pin.  In  such  a  case,  in  order  to 
avoid  a  displa}'-  of  gold,  a  full-faced  porcelain  tooth  should  be 
used.    It  should  be  cemented  into  a  gold  cup  which  spans  the 


288  MODERN  DENTISTRY 

space  between  the  inlay  in  the  molar  and  the  tooth  on  which 
the  spud  rests.    The  spud,  of  course,  in  this  instance  should  be 


Fig.  239. 

attached  to  the  side  of  the  gold  cup  into  which  the  porcelain 
dummy  is  to  be  cemented.  Figures  238-240  show  the  three 
aspects  of  such  a  bridge.     Ordinarily  the  attachment  would  be 


Fig.  240. 

made  to  the  molar  and  the  spud  would  rest  on  the  bicuspid,  but 
in  this  instance  the  attachment  is  made  to  the  bicuspid  and  the 


THE  REPLACING  OF  LOST  TEETH 


289 


spud  rests  on  the  molar,  as  the  pulp  of  the  bicuspid  had  already 
been  destroyed  and  sufficient  anchorage  was  provided. 

If  the  bridge  is  for  an  upper  tooth  and  the  patient  is  in  a 
great  hurry,  a  gold-backed  porcelain  facing  can  be  waxed  into 
position  on  the  bar  while  the  abutment  is  in  the  mouth,  and 
the  whole  safely  removed,  invested,  and  soldered  without  the 
necessity  of  making  a  model  or  an  occluding  bite.  As  before 
stated,  the  great  advantage  of  this  bridge  Hes  in  the  fact  that,  when 
it  is  set,  floss-silk  can  be  passed  under  the  little  spud  which  is 
resting  on  the  tooth  opposite  the  attachment,  and  the  whole 
surface  between  the  gold,  dummy,  and  gum  cleansed  thoroughly. 


Fig.  241.  Fig.  242. 

Figs.  241,  242. — Bridge  fastened  on  both  sides  for  greater  rigidity.  An  opening 
should  be  made  underneath  as  shown  by  circle,  through  which  silk  can  be  passed 
for  purpose  of  cleansing  gum  and  fixture. 

To  accomplish  this  the  contact  between  the  gum  and  tooth 
should  be  curved  as  Uttle  as  possible.  The  dummy  and  pro- 
jecting spud  can  obviously  be  attached  to  a  gold  crown  as  an 
abutment  if  desired.  This  principle  can  be  applied  to  a  span  of 
one  or  two  teeth,  and  it  can  be  modified  so  that  the  ends  may  be 
securely  fastened  on  each  side,  but  this  is  ordinarily  not  to  be 
preferred,  as  such  a  procedure  takes  away  the  individual  mobility 
of  each  abutment  under  the  stress  of  mastication.  It  also  makes 
it  necessary  that  a  groove  should  be  made  next  to  the  gum  for 
the  insertion  of  floss-silk  in  order  that  the  daily  cleansmg  may 
be  accomplished.  Figure  241  represents  the  labial  aspect  and 
Fig.  242  the  lingual  aspect.  The  circle  represents  the  groove 
19 


290  MODERN  DENTISTRY 

made  by  the  passage  of  a  fissure  bur  along  the  margin  of  the 
gum  and  the  abutment  neck.  The  floss-silk  can  be  threaded 
through  the  eye  of  a  blunt  needle,  and  this  passed  through  the 
opening  for  the  daily  cleansing,  but  it  is  sometimes  advisable 
to  make  a  flexible  needle  for  this  purpose  of  brass  or  gold  wire 
(see  Fig.  29).  Floss-silk  can  be  threaded  in  the  eye  of  such  a 
needle  and  be  passed  under  any  fixture  by  the  avenue  of  a 
properly  constructed  groove. 

Removable  Appliances. — ^When  a  greater  span  than  two 
teeth  is  required  the  removable  clasp  bridge  is  to  be  preferred, 
and  as  this  brings  us  to  the  final  section  of  the  chapter- — the 
replacement  of  teeth  by  clasp  fixtures — a  short  discussion  of  the 
subject  of  gold  clasps  is  appropriate.  Wherever  clasps  are  to 
be  made  or  movable  bridge  work  is  to  be  constructed,  it  is  wise 
to  run  the  model  out  in  fusible  metal. 

A 

Such  a  metal,  composed  of  8  parts  bis- 
muth, 5  parts  tin,  and  3  parts  lead, melted 
and  added  in  the  order  given,  will  make 
a  casting  that  is  easy  of  construction 
and  will  withstand  hammering  and  the 
wear  of  metal  adjustment  in  a  manner 
Fig.  243.-Correct  type  of         .^  impossible  with  plaster.     When 

clasp  for  bicuspid  or  molar.       ~i.  ir  x 

the  plaster  impression  has  been  taken, 
it  should  be  dried  for  a  few  minutes,  then  built  up  with  new 
plaster  or  moldine  to  form  a  cup,  and  the  metal  run  in  at  once. 
A  number  of  these  models  are  shown  in  figures  which  follow. 

The  clasp  should  be  composed  of  20  parts  gold,  i  of  platinum, 
2  of  copper,  and  i  of  silver.  It  should  be  very  stiff  and  springy, 
that  is,  it  should  be  sufficiently  rigid  to  withstand  the  force  of  mas- 
tication, and  yet  sufficiently  springy  to  expand  over  the  inequal- 
ities of  the  tooth  it  clasps  and  firmly  grasp  the  enamel  when  it 
has  reached  its  final  position  of  rest.  It  should  not  be  less  than 
No.  22  B.  and  S.  gage.  Many  failures  are  caused  by  having  the 
clasp  too  thin  to  do  its  work.  The  great  value  of  a  clasp  is  in 
the  spud,  with  which  it  should  always  be  provided.  For  instance, 
in  Fig.  243  A  represents  the  clasp  and  B  the  spud  that  rests  upon 
a  groove  made  in  the  grinding  surface  of  the  tooth,  so  that  the 


THE  REPLACING  OF  LOST  TEETH  29 1 

force  of  mastication  will  not  cause  it  to  slip  up  and  down  under 
the  strain  of  triturating  the  food.  This  spud  was  apparently 
first  used  by  Dr.  J.  D.  White  some  forty  years  ago,  and  later 
was  recommended  by  Dr.  Bon  will;  but  the  great  value  of  the 
spud  on  a  clasp  does  not  seem  to  have  been  generally  grasped, 
since  it  is  not  ordinarily  used.  A  clasp  that  moves  under  the 
stress  of  mastication  cuts  and  corrodes  the  enamel.    Although 


Fig.  244. — Clasp  in  position  supported        Fig.  245. — Tooth  worn  by  clasp  where 
by  spud.  no  spud  was  used. 

the  enamel  will  soften  imder  the  first  action  of  food  fermentation, 
it  hardens  again  as  the  food  fermentation  disappears  through 
proper  daily  cleansing.  If,  therefore,  the  clasp  is  held  immovable 
by  the  spud  resting  on  the  occlusal  surface  of  the  abutment,  as  in 
Fig.  244,  the  partly  softened  enamel  will  have  a  chance  to  re- 
harden  without  wear,  but  if  no  spud  is  used  upon  the  clasp, 
erosion  on  the  sides  of  the  enamel  of  the  tooth  will  most  surely 
occur,  as  in  Fig.  245.    Thus  it  is  essential  that  a  clasp  should 


Fig.  246. — Missing  bicuspid  to  be  replaced  by  a  removable  bridge  with  spring 

clasps. 

grasp  the  tooth  firmly  and  adhere  to  it  firmly  under  stress  of 
mastication.  The  simplest  form  of  clasp  plate  or  bridge  is  shown 
in  Figs.  246-248.  Here  the  sides  of  the  teeth  are  parallel,  and 
if  the  clasps  are  attached  to  the  plate  so  that  they  will  clasp  the 
largest  part  of  the  abutment,  the  procedure  is  simple  in  the  ex- 
treme. But  if  the  two  abutments  are  divergent  the  method  of 
adjusting  the  clasp  becomes  compHcated,  and  calls  for  the  great- 
est nicety  of  adjustment. 


292 


MODERN  DENTISTRY 


Divergent  Abutments. — For  instance,  in  Fig.  249  we  have  a 
first  bicuspid  elongated  and  divergent  from  the  second  molar. 
Except  for  the  divergence  of  the  axes  of  the  teeth  the  case  is 


\/j/      ^^jL  >^(i:Lji^ 


Fig.  247.^ — Gold  dummy  with  gold 
clasps  and  spud  suitable  for  filling 
space  in  Fig.  246. 


Fig.    248. — Under   surface  of   fixture 
shown  in  Fig.  247. 


ideal  for  a  clasp  plate.  But  how  to  get  the  two  clasps  into  posi- 
tion is  the  problem.  The  method  of  overcoming  this  difficulty 
is  as  follows :    A  plain,  broad  clasp  with  a  spud  attached  is  fitted 


Fig.  249. — A  difficult  span  to  restore  on  account  of  divergence  of  the  abutments. 

to  the  molar,  the  sides  of  which  should  be  ground  parallel  if 
necessary.  A  gold  plate  should  be  made  to  fit  the  gum  and  a 
clasp  should  be  adjusted  to  the  Ungual  side  of  the  bicuspid,  so 


Fig.  250.  Fig.  251. 

Figs.  250,  251. — Top  and  side  view  of  gold  clasp  that  can  be  slipped  on  at  side  of 

the  tooth. 


that  the  sides  of  the  clasp  will  extend  to  or  just  a  Httle  beyond 
the  greatest  bulge  of  the  tooth,  and  will  not  extend  over  the 
buccal  surface  at  all  (Figs.  250,  251).  The  clasps  and  plate 
should  then  be  soldered  together  in  the  position  they  are  to  occupy 


THE  REPLACING  OF  LOST  TEETH 


293 


when  finished.  The  details  of  such  a  procedure  are  so  well 
known  that  it  is  taken  for  granted  that  the  reader  is  acquainted 
with  them.  The  problem  now  is  to  adjust  the  clasps  so  that 
they  will  be  invisible  from  the  outside  of  the  mouth,  and  yet 
absolutely  rigid  when  in  final  position.  The  bicuspid  clasp  should 
be  kept  lingually  free  from  its  tooth,  while  the  molar  clasp  is 
slipped  all  the  way  down  to  its  place  on  the  molar,  and  then  a 
simple  rotation  of  the  fixture  buccally  will  push  the  prongs  of 
the  bicuspid  clasp  into  position  and  complete  stability  will  be 
obtained.  In  the  same  way  when  the  fixture  is  to  be  removed, 
the  buccal  clasp  should  first  be  disengaged  by  pushing  it  lingually 
until  the  jaws  of  the  clasp  are  entirely  free  from  the  tooth,  when 


Fig,  252. — Clasp  plate  being  slipped  into  position  where  axes  of  abutments 
diverge,  as  shown  in  Fig,  249.  Clasp  is  slipped  well  down  on  molar  B  while  the  plate  C 
is  slightly  rotated  inward,  then  the  clasp  of  the  bicuspid  A  is  forced  sideways  into 
place, 

it  will  be  a  simple  matter  to  slip  off  the  molar  clasp  from  its 
abutment.  See  Fig,  252,  Of  course,  if  an  attempt  is  made  to 
engage  both  clasps  at  once  it  will  be  impossible  to  get  the  fixti  :e 
into  position. 

Figures  253,  254  represent  a  case  in  which  all  of  the  upper 
teeth  except  the  canines  and  bicuspids  have  been  lost.  In  this 
case  a  horseshoe  plate  carrying  all  of  the  missing  teeth  is  fas- 
tened by  clasps  to  the  bicuspids,  leaving  the  hard  palate  of  the 
mouth  uncovered.  In  the  same  way  two  canines  or  bicuspids 
can  be  made  to  support  an  entire  upper  denture.  Two  clasps 
properly  adjusted  to  two  molars  on  opposite  sides  of  the  mouth 
can  readily  support  an  entire  single  denture,  and  at  a  pinch  two 
molars  on  the  same  side  can  be  made  to  do  it,  but  care  must  be 


294 


MODERN  DENTISTRY 


taken  to  trim  the  sides  of  each  molar  so  that  they  will  be  parallel 
and  give  the  maximum  support  to  the  fixture,  even  if  the  enamel 
has  to  be  cut  through.  In  such  a  case  the  teeth  can  be  capped 
with  gold  caps  with  parallel  sides  that  do  not  extend  beneath  the 


Fig.  253. 


Fig.  254. 
Figs.  253,  254. — Upper  denture  supported  by  two  canines. 


gum;  and  if  the  teeth  are  sensitive  to  heat  and  cold,  it  is  always 
good  practice  in  any  case  to  destroy  the  pulp  and  carefully  fill 
the  canals.  The  following  illustrations  show  some  interesting 
types  of  fixtures  capable  of  being  successfully  fastened  into  posi- 


THE  REPLACING  OF  LOST  TEETH  295 

tion  by  clasps.    Figure  255  represents  the  two  aspects  of  a  fin- 
ished plate.     Figure  256  shows  the  gold  plate  before  the  teeth 


Fig.  255. — Under  and  upper  view  of  lower  denture  supported  by  two  bicuspids 

and  a  molar. 

are  added,  and  the  fusible  metal  model.  Figure  257  represents 
an  interesting  illustration  of  an  upper  and  lower  restoration 
on  the  right  side  of  the  mouth.     A  represents  the  fusible  metal 


Fig.  256.— Figure  on  the  left  represents  the  gold  plate  and  clasps  of  Fig.  255  before 
the  teeth  are  added.     On  the  right  is  the  fusible  metal  model. 

models  on  an  articulator,  B  represents  the  upper  fixture,  C  the 
lower  fixture,  D  and  E  represent  the  gold  plates  of  these  fixtures 
before  the  teeth  are  added,  F  and  G  represent  respectively  the 


296 


MODERN  DENTISTRY 


i^^    v'  A 


r^. 


''^~::s^ 


D 


y'lj^'^—Xm^. 


Fig.  257. — A,  A,  Upper  and  lower  fusible  metal  models;  D,  E  respectively, 
upper  and  lower  gold  fixtures  before  teeth  are  added;  B,  F,  two  views  of  finished 
upper  fixture;  C,  G,  lower  finished  fixture. 


THE   REPLACING   OF   LOST   TEETH 


297 


gum  aspects  of  the  two  fixtures  when  finished.  Figure  258 
represents  the  lingual  aspect  of  the  unfinished  plates  in  position 
on  the  model. 


Fig.  258. — Lingual  view  of  plates  and  models  just  described. 


Fig.  259. — Upper  removable  clasp  bridge. 


Figures  259-261  represent  a  removable  bridge  that  is  inter- 
esting on  account  of  the  concealed  gold  clasp  on  the  bicuspid. 
A  is  a  gold-crowned  second  molar  with  parallel  sides,  B  is  a 


298  MODERN  DENTISTRY 

porcelain-faced  gold-backed  bicuspid.  The  problem  was  to 
make  a  bridge  that  would  not  show  the  gold  clasp  at  the  neck 
oi  B.  A  broad  gold  clasp  was  made  for  ^ .  A  pit  and  groove 
were  made  in  the  grinding  surface  oi  B,  as  is  shown  by  the  dotted 


Fig.  260. — Labial  aspect  of  bridge  in  position. 

lines  (Fig.  260).  In  Fig.  261  a  bent  bar  and  half  clasp  were 
adjusted,  as  is  shown  by  C  and  D,  the  attachment  to  the  bicuspid 
being  obtained  by  grasping  the  inner  cusp  between  the  pin  D 
and  the  half  clasp  C.    Figures  260  and  261  show  the  labial  and 


Fig.  261.- — Buccal  aspect  of  bridge  in  position. 

buccal  aspects  of  the  bridge  in  position,  while  the  bridge  itself 
is  shown  in  Fig.  259. 

The  Double   Clasp  Bridge. — There  is  one  type  of  fixture, 
however,  that  deserves  special  mention,  and  that  is  the  fixture 


THE  REPLACING  OF  LOST  TEETH 


299 


that  replaces  two  molars  or  a  molar  and  bicuspid  and  is  attached 
on  only  one  side  by  a  double  clasp  or  a  clasp  and  elongation  of 
the  plate.  A  case  of  special  interest  is  one  showing  the  construc- 
tion of  an  all-porcelain  bridge  attached  to  the  abutment  by  a 
double  gold  clasp  and  spud  (Figs.  262,  263).  As  observed,  the 
teeth  back  of  the  second  bicuspid  are  missing.  B  represents 
the  gold  clasp,  No.  22  gage,  fitted  to  the  second  bicuspid,  to  the 
ends  of  which  clasp  are  added  gold  projections,  C,  which  half 
embrace  the  first  bicuspid  near  the  gum  hne.  A  piece  of  pure 
gold,  No.  35  B.  &  S.,  is  soldered  to  the  clasp  at  the  posterior 
aspect  of  the  second  bicuspid  and  burnished  into  the  occlusal 
groove  prepared  to  receive  it.    When  this  is  stiffened  with  half- 


Fig.  262. — Lingual  view  of  all-porcelain  bridge  with  gold  clasp  in  process  of  con- 
struction. 


round  platinized  gold  wire  and  solder  it  will  form  the  spud  A 
that  will  prevent  the  clasp  from  being  driven  into  the  gum  by  the 
force  of  mastication.  If  the  occluding  tooth  should  interfere 
with  the  spud,  the  tooth  should  be  correspondingly  shortened. 
The  clasp  and  spud  should  now  be  poUshed  to  the  lines  desired, 
and  a  thin  coating  of  borax  flowed  over  them  so  as  to  expedite 
future  soldering.  They  should  then  be  placed  upon  the  model  and 
a  right-angled  piece  of  No.  14  iridio  platinum  wire,  represented 
by  D,  should  be  adjusted  to  it  at  the  gum  hne.  E  represents 
platinum  foil,  o.ooi  inch  thick,  burnished  and  trimmed  to  fit 
the  model.  The  angle  wire,  D,  should  be  placed  in  position 
on  it;  continuous  gum  porcelain  body  placed  on  the  angle  wire; 


300  MODEEN  DENTISTRY 

and  platinum  foil  and  rubber  teeth  of  suitable  size  and  shade 
placed  upon  the  body,  just  as  in  the  preparation  of  the  wax  model 
of  a  rubber  case.  When  the  body  has  been  carved  to  the  proper 
lines  of  the  gum,  the  platinum  foil,  angle,  bar,  teeth,  and  body 
should  all  be  removed  together,  placed  in  the  oven  and  given 
a  thorough  glaze.  When  the  porcelain  is  cool  the  platinum  foil 
should  be  stripped  off  and  new  foil  burnished  to  the  model.  A 
thin  layer  of  porcelain  paste  should  then  be  placed  on  the  plati- 
num foil  and  the  porcelain  block  pressed  and  tapped  down  upon 
it  until  the  articulation  is  just  a  Little  high.  This  extra  height 
is  necessary  in  order  that  perfect  occlusion  may  be  obtained  by 
grinding  when  the  case  is  finally  fitted  in  the  mouth.  The  ad- 
ditional porcelain  paste  is  necessary  to  make  up  for  the  contrac- 
tion caused  by  the  fusing  of  the  porcelain  piece  in  the  first  bake. 


Fig.  263. — Buccal  view  of  finished  all-porcelain  bridge  with  gold  clasp  for  attach- 
ment. 

When  the  porcelain  has  been  carved  a  second  time  to  a  satis- 
factory line,  it  is  removed  again  on  the  platinum  foil  and  placed 
in  the  oven  for  another  baking.  After  baking  and  after  the 
platinum  foil  is  removed,  the  porcelain  block  should  accurately 
fit  the  model.  If  pink  gum  enamel  is  necessary  there  will  have 
to  be  a  third  baking,  but  for  this  no  platinum  foil  will  be  needed 
to  preserve  the  contour,  as  the  first  body  fuses  at  a  higher  point 
than  the  enamel.  When  the  porcelain  block  is  finished,  we  have 
a  double  clasp  with  a  spud  and  a  porcelain  block  with  a  platinum 
bar  running  through  it.  It  now  remains  to  join  them  together. 
The  clasp  is  placed  in  position  on  the  model;  the  end  of  the  porce- 
lain block  that  goes  next  to  the  clasp  is  ground  until  the  platinum 
bar  is  clean  and  fresh  enough  to  receive  the  solder.  Then  to 
the  end  of  the  ground  porcelain  a  thin  backing  of  pure  gold 
should  be  burnished  to  make  a  tight  joint  with  the  porcelain, 


THE  REPLACING  OF  LOST  TEETH 


301 


and  held  in  place  with  a  little  hard  wax.  The  middle  of  this 
backing  should  be  torn  so  as  to  expose  the  platinum  and  make  it 
possible  to  solder  together  the  clasp,  gold  backing,  and  platinum 
bar.  The  clasp  and  porcelain  should  then  be  placed  on  the  cast 
and  waxed  into  accurate  position.  They  are  then  removed, 
invested,  and  soldered  in  the  usual  way.    Figure  263  represents 


Fig.  264 


Fig.  265. 


Fig.  266. 
Figs.  264-266. — Three  aspects  of  a  double  clasp  bridge  with  gold  plate  and  vul- 
canite attachment. 


the  finished  piece.  It  might  be  well  to  state  that  varnishing 
the  gum  enamel  with  gum  shellac  varnish  prevents  the  invest- 
ment from  sticking  to  it  during  the  process  of  soldering. 

It  is  obvious  that  after  the  double  clasp  has  been  made  as 
just  described,  instead  of  using  porcelain,  a  gold  plate  can  be 
swaged,  fitted,  and  soldered  to  the  clasp.    Porcelain  teeth  can  be 


302 


MODERN   DENTISTRY 


Fig.  267. 


Fig.  268. 


Fig.  269. 


Fig.  270. 

Figs.  267-270. — Double  clasp  bridge  attached  to  natural  teeth  on  one  side  only. 

Composed  of  gold  plate  and  teeth  cemented  into  suitably  prepared  gold  box. 


attached  to  this  plate  with  vulcanite,  as  is  shown  in  Figs.  264- 
266.  In  this  instance  the  single  clasp  is  used  externally  and  the 
double  support  is  given  on  the  inside  alone. 


THE  REPLACING  OF  LOST  TEETH 


303 


The  All-gold  and  Porcelain  Fixture.— Where  it  is  desired 
to  have  teeth  cemented  into  gold  so  that  only  the  gold  and  porce- 
lain will  show,  the  procedure  is  simple  and  easy.  The  plate  and 
clasp  should  be  made  as  usual  and  the  teeth  adjusted  and  waxed 
into  position  (Fig.  267).  Then  a  piece  of  No.  30  pure  gold  should 
be  fitted  and  burnished  around  the  buccal  margins  of  the  teeth 
and  plate,  as  shown  in  Fig.  268.    The  teeth  and  supporting  wax 


Fig.  271. 


Fig   272. 


Fig.  273. 
Figs.  271-273. — Removable  gold  and  porcelain  bridge  attached  to  natural 
teeth  on  one  side  only.    Teeth  are  set  in  gold  cups  built  into  position  with  sponge 
gold  and  finally  filled  full  of  22-karat  solder. 

are  then  removed  and  the  burnished  gold.  A,  soldered  to  the 
plate.  The  teeth  should  then  be  replaced  on  the  plate  and  another 
piece  of  gold,  designated  by  B,  adjusted  on  the  palatal  side 
(Fig.  269).  The  ends  should  lap  behind  the  molar.  The  teeth 
are  once  more  removed  and  the  gold  soldered  to  form  a  perfectly 
fitting  gold  box  (Fig.  270),  into  which  the  teeth  can  be  cemented 
with  silicious  cement. 


304  .        MODERN  DENTISTRY 

Figures  271-273  show  a  method  of  fastening  the  teeth  to  the 
plate  by  means  of  gold  cups,  which  gold  cups  are  built  up  into 
position  by  sponge  gold,  which  is  later  filled  full  of  gold  solder. 
Figure  271  shows  the  lingual  side  of  the  same  tj^e  of  plate  with 
the  molar  and  bicuspid  in  position.  Gold  cups  made  of  0.003 
inch  pure  gold  have  been  adjusted  to  the  porcelain  as  is  shown 
in  the  illustration.  Then  a  thin  film  of  hard  wax  is  flowed  over 
the  base  of  the  gold  cups  and  the  adjacent  plate,  and  sponge 
gold  is  rapidly  and  firmly  packed  in  around  the  teeth  and  between 
the  teeth  and  plate  (Fig.  272).  If  necessary  a  little  hard  wax 
can  be  flowed  into  the  sponge  gold  to  add  to  its  adhesiveness. 
Then  the  teeth  can  be  coaxed  out  of  the  cups,  as  shown  in  Fig. 


Fig.  274. — Interesting  type  of  removable  denture  composed  of  gold  and  porcelain 

only. 

273,  and  the  entire  sponge  gold  mass  filled  with  solder.  An 
investment  may  be  used,  but  usually  it  is  unnecessary.  When 
the  teeth  are  cemented  into  the  cups  the  porcelain  and  gold  alone 
are  visible. 

Figures  274-277  represent  a  completed  plate  composed  of  gold 
and  porcelain  made  on  the  principle  of  the  gold  cup  method 
just  described. 

The  cases  might  be  multiplied  indefinitely,  but  if  the  prin- 
ciples demonstrated  are  judiciously  appHed  it  will  be  found  that 
any  partial,  movable  denture  can  be  readily  made. 

The  method  of  making  full  upper  and  lower  dentures  sup- 
ported by  suction  has  not  been  discussed,  as  the  procedure  is 


THE  REPLACING  OF  LOST  TEETH 


305 


Fig.  275. 


Fig.  276. 


Fig.  277. 


3o6  MODERN  DENTISTRY 

well  known,  and  success  depends  largely  upon  the  adaptabiKty 
of  the  mouth  of  the  patient.  But  where  a  single  tooth  can  be 
saved  to  act  as  a  support  for  what  would  otherwise  be  a  full  upper 
or  lower  denture,  the  efficiency  for  mastication  will  ordinarily 
be  increased  loo  per  cent,  and  the  peace  of  mind  of  the  patient 
will  be  assured  by  the  certain  knowledge  that  the  plate  will  not 
suddenly  become  dislodged,  to  his  mortification  and  annoyance. 
In  such  a  case  a  well-fitting  clasp  will  prove  of  invaluable  assist- 
ance. 

The  normal  tooth  matches  the  undertone  of  the  skin.  There- 
fore, in  full  dentures  where  there  are  no  teeth  from  which  to  obtain 
the  color,  the  following  expedient  may  be  used:  The  skin  of  the 
patient  should  be  pressed  and  the  color  noted  before  the  blood 
returns  to  the  capillaries.  On  a  cold  day  this  method  will  be 
particularly  effective. 


CHAPTER  XI 

EXPERIMENTS  CONCERNING  THE   STRENGTH,   SOLU- 
BILITY, AND  ADHESIVENESS  OF  VARIOUS  CEMENTS 

Silicious  Cements. — Dr.  Ames,  the  great  authority  on  dental 
cements,  says  that  "the  sihcious  cements  are  really  oxyphosphate 
of  calcium,  and  should  be  considered  as  being  so  compounded 
that  the  cement-making  phenomenon  comes  from  the  action  of 
phosphoric  acid  on  calcium  oxid  or  basic  calcium  silicate,  the 
action  being  retarded  by  the  intimate  blend  with  alumina  and 
silica."  The  action  on  calcium  oxid  alone  would  be  very  violent. 
The  alumina  and  silica  act  as  diluents  and  give  integrity  to  the 
resulting  mass.  The  formulae  of  the  various  cement  powders  are 
practically  identical  with  that  of  calcium  feldspar.  Feldspar 
furnishes  the  chief  ingredient  of  porcelain,  and  these  cements, 
therefore,  may  reasonably  be  considered  porcelain  in  which 
there  is  agglutination  by  chemical  action  instead  of  agglutination 
by  heat. 

The  term  "silicious  cement"  is  more  accurately  descriptive 
than  the  term  "silicate  cement."  Normal  silicates  do  not  afford 
cement-making  properties.    Sihcious  mixtures  may. 

Silicious  cements  will  present  no  difficulties  in  manipulation 
if  the  setting  process  is  considered  as  being  practically  that 
of  the  oxyphosphates.  Mixing  cements  upon  a  slab  of  known 
temperature  has  become  a  habit  with  a  large  number  of  operators. 
This  is  accomplished  by  using  the  flat  side  of  a  bottle  containing 
water  of  the  temperature  desired  (Fig.  278),  which  temperature 
is  ascertained '  by  a  thermometer  inserted  through  the  cork. 
Cold  spigot-water  ordinarily  is  sufficient  to  carry  off  the  heat 
of  the  chemical  reaction,  but  for  those  who  wish  to  make  the 
water  colder,  almost  to  the  dew  point,  a  wet  and  dry  bulb  hydrom- 
eter is  a  great  convenience.  The  colder  the  slab  is  kept,  with- 
out excess  moisture  being  precipitated  from  the  air,  the  greater 
length  of  time  will  there  be  for  the  manipulation  of  the  cements. 

307 


3o8 


MODERN  DENTISTRY 


When  setting  occurs  in  a  judiciously  constructed  silicious 
cement  the  chemical  balance  is  automatically  established.  As 
the  warmth  of  the  tooth  is  imparted  to  the  cement,  the  proper 
amount  of  liquid  and  powder  tend  to  com- 
bine, and  the  crystallization  begins  next 
to  the  tooth,  continuing  toward  the  center 
of  the  mass.  If  the  hquid  has  been  in 
excess  in  the  mixture  it  will  be  left  on  the 
surface,  and  if  there  has  been  a  shortage 
of  liquid  and  an  excess  of  powder,  the  final 
surface  will  have  a  honeycombed  appear- 
ance. For  these  reasons  it  is  wise  to 
have  sufficient  liquid  to  make  the  surface 
slightly  moist  when  the  cement  is  being 
inserted,  and  any  excess  moisture  may  then 
be  finally  taken  up  by  an  application  of 
powder.  Sufficient  time  should  always  be 
allowed  for  the  proper  introduction  of 
the  cement  into  the  cavity,  as  the  struc- 
ture of  silicious  cement  is  seriously  injured 
if  it  is  manipulated  after  the  process  of 
crystallization  has  actually  begun. 

When  the  cement  is  in  position  and  has 
started  to  set  it  is  sometimes  good  practice 
to  flow  hot  parafiin  upon  it.  This  will 
cause  a  prompt  setting,  and  will  tend  to 
save  the  time  of  the  operator  and  prevent 
the  dilution  with  saliva  of  the  uncombined 
ingredients.  It  will  also  tend  to  remove  any 
risk  of  the  pulp  being  injured  by  the  free 
acid.  If  such  a  risk  exists,  however,  it  can 
readily  be  obviated  by  lining  the  cavity 
with  varnish  prior  to  the  insertion  of  the 
filling.  Ordinarily  such  a  precaution  is  not 
necessary,  but  where  there  is  a  near  approach  to  the  pulp  it  is 
always  wise  to  use  the  cavity  hning.  In  cases  where  the  pulps 
are  supposed  to  die  from  the  action  of  the  cement,  there  is  always 


Fig.  278. — The  Ames 
cement  slab — a  flat- 
sided  bottle  filled  with 
cold  water,  on  which 
cement  can  be  mixed. 


EXPERIMENTS   CONCERNING  VARIOUS   CEMENTS  309 

a  question  whether  the  pulp  died  from  the  action  of  the  cement 
ingredients,  or  whether  it  had  not  already  been  fatally  attacked 
by  infection  before  the  filling  was  inserted. 

The  adhesion  of  sihcious  cements  counteracts  a  possible 
tendency  toward  shrinkage  because  of  the  adhesion  to  the  cavity 
wall.  This  adhesion,  while  the  cement  is  soft,  will  cause  a  shrink- 
age toward  the  wall  rather  than  away  from  it,  since  the  cement 
in  contact  with  the  cavity  wall  is  the  first  portion  to  set  because 
of  the  heat  imparted  by  the  tooth. 

Phosphate  of  Zinc  Cements.— The  following  experunents 
were  made  some  years  ago  with  phosphate  of  zinc  cements  before 
the  introduction  of  sihcious  cements;  and  although  the  sihcious 
cements  by  their  msolubility  have  made  these  tests  on  the  solu- 
bihty  of  phosphate  cement  films  of  less  importance,  nevertheless, 
since  phosphate  cement  is  still  so  universally  used  for  the  re- 
tention of  crowns,  bridges,  and  bands,  these  experiments  are 
reported  with  the  hope  that  not  only  the  facts  brought  to  hght 
may  prove  of  value,  but  also  that  the  technic  of  the  experimen- 
tation may  be  of  use  in  aidmg  those  who  would  like  to  extend 
the  scope  of  these  experiments. 

Before  the  days  of  sihcious  cements  the  phosphate  of  zinc 
cement  hne  arising  from  the  removal  of  the  matrix  was  always  a 
subject  of  general  criticism  and  discussion  in  porcelain  inlay 
work.  By  some  it  was  deemed  a  great  advantage  to  use  No.  30 
gold  foil  for  a  matrix.  This  was  so  because  No.  30  gold  foil  is 
one-third  the  thickness  of  the  o.ooi-inch  platmum  foil.  There- 
fore, the  gold  was  beheved  to  make  a  finished  filhng  that  would 
leave  a  cement  fine  one-third  the  thickness  of  the  cement  line 
of  a  filling  where  the  platuium  matrix  was  used. 

These  and  other  statements  prompted  me  to  undertake 
experiments  for  the  purpose  of  solving  the  following  questions: 
A.  (i)  What  is  the  minimum  line  of  cement  that  can  be 
obtained  at  the  edges  of  an  inlay?  (2)  Is  maintained  pressure 
until  the  cement  sets  or  fineness  of  cement  grit  the  more  respon- 
sible for  obtaining  a  fine  cement  Hne  ?  (3)  Is  it  of  any  practical 
value  to  maintain  pressure  for  more  than  a  minute  while  the 
cement  is  setting  ? 


3IO  MODERN  DENTISTRY 

B.  (i)  Does  a  thick  or  thin  line  of  cement  give  the  greater 
strength  of  retention  ?  (2)  Is  a  fine  grit  or  coarse  grit  cement 
the  stronger  ? 

C.  (i)  What  is  the  adhesive  strength  of  glazed  porcelain 
cemented  to  smooth  ivory  ?  (2)  What  is  the  adhesive  strength 
of  etched  porcelain  cemented  to  smooth  ivory?  (3)  What  is 
the  adhesive  strength  of  etched  porcelain  cemented  to  undercut 
ivory  ?  (4)  What  is  the  adhesive  strength  of  undercut  porcelain 
cemented  to  undercut  ivory  ? 

Tests  on  Cement  Line. — To  ascertain  the  minimum  thickness 
of  the  cement  line  pieces  -of  glass  |-inch  square  were  cemented 
to  pieces  of  glass  ^-inch  square.  These  pieces  of  glass  were  so 
true  as  to  permit  atmospheric  suction  when  pressed  together  in 
a  dry  state.  To  facilitate  the  removal  of  the  cement  film  the 
surface  was  slightly  oiled  by  rubbing  on  the  skin.  Pressures 
of  8,  25,  50,  and  100  pounds  were  used  with  various  grits  of  the 
Harvard  cement,  as  well  as  with  Ames'  inlay  cement,  to  see 
whether  pressure  or  fineness  of  grit  was  the  more  responsible 
for  the  thin  cement  line.  These  pressures  in  half  the  number 
of  instances  were  maintained  for  a  minute  only,  and  the  further 
setting  continued  without  external  pressure.  With  the  other 
half  the  pressure  was  maintained  until  the  setting  was  complete. 
This  was  done  to  see  if  the  maintaining  of  the  pressure  for  more 
than  one  minute  was  of  any  practical  value  in  reducing  the 
cement  line.  The  J-inch  square  film  was  chosen  as  a  standard 
cement  surface.  This  is  larger  than  the  average  surface  of  a 
porcelain  inlay,  but  as  from  2  to  6  pounds  was  found  from  experi- 
ment to  be  the  pressure  ordinarily  applied  to  the  average  fillings 
in  the  mouth,  it  was  considered  that  definite  conclusions  could 
be  obtained  from  8,  25,  50,  and  100  pounds  pressure  applied  to 
films  ^-inch  square,  and  that  these  films  would  be  large  enough 
to  measure  at  several  points  and  give  an  average  thickness.  The 
measurements  for  thickness  were  made  with  the  Black  amalgam 
micrometer,  and  those  for  pressure  with  the  Black  dynamometer. 

All  of  the  cement  films  were  allowed  to  set  in  a  dry  state, 
and  it  was  found  that  when  they  were  dipped  in  water  the  glass 
pieces  separated  and  the  complete  film  was  easily  dislodged  and 


EXPERIMENTS   CONCERNING  VARIOUS   CEMENTS  3II 

floated  off.    It  was  then  picked  up  on  a  camel's-hair  brush  and 
attached  to  the  face  plate  of  the  micrometer,  when  the  various 
readings  were  obtained  by  moving  the  film  of  cement  on  the  face 
plate  under  the  measuring  terminal.    The  film  of  water  between 
the  cement  film  and  the  face  plate  was  found  to  be  o.oooi  inch 
in  thickness  in  the  following  way:    A  reading  was  taken  while 
the  wet  film  of  cement  was  still  adherent  to  one  of  the  glass 
pieces.     The  cement  film  was  then  loosened  so  that  a  film  of 
water  could  creep  underneath  and  the  reading  again  taken. 
By  numerous  such  tests  the  water  fihn  was  found  to  be  o.oooi 
inch.    Thus  o.oooi  inch  will  be  deducted  from  every  reading 
given   in   the   tables   of  film   measurements    unless    otherwise 
stated.     The  readings  of  the  Black  amalgam  micrometer  were 
controUed   by  the    Brown    &   Sharpe   micrometer,   and  while 
the  Brown  &  Sharpe  micrometer  could  not  measure  quite  so 
minutely  as  the  Black,  in  so  far  as  they  could  be  compared,  the 
measurements  for  both  instruments  were  the  same.    The  pres- 
sure generaUy  used  in  cementing  fillings  in  the  mouth  was  arrived 
at  in  the  following  manner:    Porcelain  inlays  having  a  surface 
about  i-inch  square  were  made  to  fit  cavities  in  a  block  of  ivory. 
This  block  was  then  placed  on  scales  and  the  fiUings  cemented 
into  position.    Without  looking  at  the  dial,  pressures  were  used 
such  as  were  felt  to  be  ordinarily  used  in  the  mouth,  while  an 
assistant  noted  the  readings.    It  was  found  that  2  pounds  was 
the  pressure  used  where  there  were  frail  edges,  3  to  4  pounds 
were  safely  appUed  to  ordinary  filHngs,  and  6  pounds  seemed 
the  maximum  pressure  that  would  ordinarily  be  appHed  to  a 
filHng  with  a  surface  |-mch  square.     This  equals  i  pound  for 
frail  filHngs  of  i^-inch  square   surface.    These  measurements 
on  the  force  usually  apphed  in  the  mouth  make  the  tests  of  8 
and  25  pounds  pressure  the  only  ones  of  practical  working  value, 
but,  as  previously  stated,  films  of  cement  were  also  made  under 
50  and  100  pounds  pressure  to  determine  the  minimum  cement 
line,  and  to  determine  whether  the  pressure  under  which  the 
cement  was  set  or  the  fineness  of  the  grit  was  the  more  re- 
sponsible for  the  minimum  fine. 

Of  the  Harvard  cement  four  different  grits  were  used:    (i) 


312  MODERN   DENTISTRY 

Harvard  coarse,  such  as  was  ordinarily  used  for  making  fillings 
and  such  as  was  for  a  long  time  ordinarily  used  for  cementing 
inlays.  (2)  Harvard  inlay  cement,  as  prepared  for  Dr.  Jenkins. 
(3)  A  finer  grit  Harvard  which  I  had  especially  prepared  and 
used  up  to  the  time  of  these  tests.  This  I  shall  speak  of  as  the 
Harvard  special.  (4)  A  Harvard  cement  pulverized  in  an  agate 
mortar  until  the  grit  was  almost  imperceptible  to  the  teeth,  and 
which  will  be  referred  to  as  Harvard  pulverized. 

No  use  was  made  of  a  reduced  grit  of  the  Ames  inlay  cement, 
as  it  was  found  that  any  reduction  of  the  powder  so  hastened 
the  setting  as  to  render  it  unavailable. 

Using  8  pounds  pressure  for  one  minute  the  average  thickness 
of  the  cement  was  found  to  be  as  follows : 

Harvard  coarse 0024  inch 

Harvard  inlay 0017     " 

Harvard  special 0015     " 

Harvard  pulverized 0003     " 

Ames  inlay 0010     " 

(See  Tables  1-6,  13-15.) 

The  tests  of  25,  50,  and  100  pounds  pressure  were  made 
only  on  the  Harvard  special  and  the  Ames  inlay  cement.  (See 
Tables  7  to  12,  16  to  21.)  These  were  only  of  interest  in  showing 
that  there  was  an  inverse  ratio  between  the  pressure  and  the 
cement  line.  In  other  words,  the  greater  the  pressure,  the  finer 
the  Hne  obtained.  The  Harvard  special  at  100  pounds  gave  a 
line  0.0009  iiich  in  thickness  and  the  Ames  at  100  pounds  gave 
a  line  0.0006  inch  in  thickness,  while  the  Harvard  pulverized 
at  but  8  pounds  gave  a  line  less  than  0.0003  inch.  Therefore 
it  seems  that  a  finer  grit  is  a  much  more  important  factor  than 
pressure  in  obtaining  a  fine  hne. 

Maintaining  the  pressure  until  setting  was  complete  instead 
of  maintaining  it  for  one  minute,  was  found  to  result  in  a  differ- 
ence of  only  0.00005  inch,  a  difference  less  than  the  probable 
working  error  of  the  operator.  The  result  was  obtained  by  taking 
the  general  average  of  all  the  films  made  under  maintained  pres- 
sure and  comparing  it  with  the  general  average  of  all  the  films 
set  under  a  pressure  for  one  minute  only.    However,  though  this 


EXPERIMENTS    CONCERNING   VARIOUS    CEMENTS 


313 


is  of  little  importance  in  reducing  the  cement  line,  it  is  possible 
that  it  is  of  great  importance  in  increasing  the  adhesion.  This 
will  be  discussed  later. 

In  preparing  each  of  the  following  tables  five  and  occasionally 
six  or  seven  measurements  were  taken  on  each  of  five  similar 
films. 

TABLE   I.— HARVARD    COARSE   W. 

Harvard  coarse  W  =  Harvard  coarse  grit,  pressure  8  pounds  on  one-quarter 
inch  square  glass  for  i  minute. 

Water  film  that  floated  cement  on  face  plate  measured  o.oooi  inch.  Therefore, 
o.oooi  inch  should  be  subtracted  from  each  result  as  an  error  due  to  measuring  the 
water  film  with  the  cement  film. 


Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.00275 

.0026 

•00255 

.0027 

.00265 

= 

.00250 

,00245 

.00265 

.00270 

.00250 

.00260 

= 

.00258 

.00242 

.00215 

.00225 

.00250 

.00236 

= 

.002526 

,00242 

.00260 

.00280 

.00265 

.00265 

= 

.002624 

,00220 

.00266 

.00230 

.00220 

.00225 

= 

.002442 

General  average,  .002534  inch. 
Corrected  average,  .002434  inch. 

TABLE   2.— HARVARD   COARSE  W 

Harvard  coarse  W'  same  as  Harvard  coarse  W  except  that  pressure  is  main- 
tained until  setting  is  complete. 


Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.00260 

.00285 

.00270 

.00270 

.00260 

= 

.00269 

.00230 

.00235 

.00225 

.00215 

.00215 

= 

.00226 

.00280 

.00272 

.00250 

.00276 

.00284 

= 

.002724 

.00290 

.00300 

.00284 

.00294 

.00290 

= 

.002901 

.00250 

.00250 

.00250 

.00245 

.00245 

= 

.002408 

General  average,  .002596  inch. 
Corrected  average,  .002496  inch. 


TABLE  3.— HARVARD   INLAY  W 

Harvard  inlay  W  =  Harvard  inlay  cement,  one-quarter  inch  square  glass, 
8  pounds  pressure  for  i  minute  and  then  released  until  setting  occurs. 


Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.00175 

.00180 

.00180 

.00185 

.00180 

= 

.0018 

.00165 

.00182 

.00186 

.00186 

.00165 

= 

.00179 

.00180 

.00175 

.00165 

.00176 

.00180 

= 

.00173 

.00170 

.00180 

.00192 

.00185 

.00180 

= 

.00181 

.00178 

.00185 

.00184 

.00175 

.00175 

= 

.00179 

General  average,  .00178  inch. 
Corrected  average,  .00168  inch. 


314  MODERN  DENTISTRY 

TABLE  4.— HARVARD  INLAY  W 

Harvard  inlay  W'  =  Harvard  inlay  W,  8  pounds  pressure  maintained  until 
complete  setting  occurs. 

Water  film  that  floated  cement  on  face  plate  measured  o.oooi  inch.  Therefore, 
o.oooi  inch  should  be  subtracted  from  each  result  as  an  error  due  to  measuring 
the  water  film  with  the  cement  film. 


Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.00180 

.00170 

.00160 

.00175 

.00170 

= 

.00171 

.00175 

.00188 

.00175 

.00175 

.00175 

= 

.00177 

.00185 

.00195 

.00190 

.00195 

.00190 

= 

.00195 

.00205 

.00172 

.00195 

.00185 

.00195 

= 

.00194 

.00165 

.00170 

.00175 

.00170 

.00160 

= 

.00168 

General  average,  .00181  inch. 
Corrected  average,  .00171  inch. 

TABLE  5.— HARVARD   SPECIAL  W 

Harvard  Special  =  Harvard  cement  especially  prepared  for  Dr.  Head  and 
used  by  him  before  these  tests  were  undertaken. 

Harvard  Special  W  =  Harvard  special,  one-quarter  inch  glass,  8  pounds  pressure 
for  I  minute  and  released  =  one-eighth  inch  glass  under  2  pounds  pressure. 

Water  film  that  floated  cement  on  face  plate  measured  0.0001  inch.  There- 
fore, O.OOOI  inch  should  be  subtracted  from  each  result  as  an  error  due  to  measur- 
ing the  water  film  with  the  cement  fihn. 


Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.0015 

.00145 

•00155 

•00155 

•00155 

=    .00152 

.0017 

.0018 

.0019 

.0017 

.0019 

=    .0018 

.00195 

.0015 

.0018 

.0017 

.00195 

=    .00176 

.00155 

.00155 

.00165 

.00165 

.0016 

=    .0016 

.0015 

•00155 

.0016 

.0017 

.0018 

=    .00163 

General  average,  .00166. 
Corrected  average,  .00156  inch. 

TABLE   6.— HARVARD   SPECIAL   W' 

Harvard  Special  W'  =  same  as  Harvard  Special  W,  only  pressure  is  continued 
for  15  minutes  or  until  set. 


Inch 

Inch 

Inch 

Inch 

Inch 

Average 

•0015 

.0016 

.0015 

.0017 

.00175 

= 

.00161 

.00145 

.0015 

.00165 

.0016 

.00145 

= 

.00153 

.00195 

.00175 

.0018 

.0017 

.00195 

= 

.00171 

.00145 

.00155 

.0016 

.00175 

.0018 

= 

.00163 

.0016 

.0018 

.0017 

.00145 

00165 

= 

.00164 

General  Average,  .00162  inch. 
Corrected  average,  .00152  inch. 


EXPERIMENTS   CONCERNING   VARIOUS   CEMENTS 


315 


TABLE   7.— HARVARD   SPECIAL  X 

Harvard  Special  X  =  Harvard  special,  25  pounds  pressure  for  i  minute  and 
released. 

Water  film  that  floated  cement  on  face  plate  measured  o.oooi  inch.  Therefore, 
o.oooi  inch  should  be  subtracted  from  each  result  as  an  error  due  to  measuring 
the  water  film  with  the  cement  film. 

Inch 

•00155 

.00148 

.00160 

.00164 

.00162 


Inch 

Inch 

Inch 

.00145 

.00155 

•00155 

•0015s 

.00142 

.00145 

.00145 

.00130 

.00148 

.00160 

.00152 

.00144 

.00150 

.00172 

.00161 

Inch 

Average 

= 

.00152 

.00134 

= 

•00155 

.00145 

= 

•00145 

.00155 

= 

•00155 

.00152 

= 

•00159 

General  average,  .00153  inch. 


Corrected  average,  .00143  inch. 


TABLE  8.— HARVARD  SPECIAL  X' 

Harvard  special  X'  =  Harvard  special,  25  pounds  pressure  until  set,  or  about 
30  minutes. 

Inch 
.0016 
.00120 
.00125 
.00130 
.00110 


Inch 

Inch 

Inch 

.0016 

.00135 

.0013 

.00125 

.00115 

.00120 

.00132 

.00125 

.00134 

.00132 

.00132 

.00125 

.00110 

.00122 

.00110 

Inch 

Inch 

Average 

.0013 

.0014 

= 

.00145 

.00135 

= 

.00145 

.00130 

= 

.00129 

.00130 

= 

.00130 

.00108 

= 

.00129 

General  average,  .00135  inch. 


Corrected  average,  .00125  inch. 


TABLE  9.— HARVARD  SPECIAL  Y 

Harvard  special  Y  =  Harvard  special,  under  50  pounds  pressure,  one-quarter 
inch  glass,  i  minute  and  then  released. 

Inch            Inch           Inch           Inch  Inch  Average 

.00125  =  .00129 

.00098  .00080         =  .000976 

.00135  .00135         =  .00136 

.00100  .00085         ~  .00094 

.00135  .00135         =  .00124 


.00120 

.00125 

.00145 

.00105 

.00120 

.00085 

.00120 

.00145 

.00145 

.00090 

.00100 

.00095 

.00160 

.00140 

.00150 

General  average,  .00116  inch. 


Corrected  average,  .00106  inch. 


TABLE   10.— HARVARD   SPECIAL  Y' 

Harvard  special  Y'  =  Harvard  special,  under  50  pounds  pressure,  one-quarter 
inch  glass,  until  set. 


Inch 
.00125 
.00135 
.00130 
•oono 
.00135 


Inch 
.0015 
.00140 
.00115 
.00115 
.00110 


Inch 
.00125 
.00130 
.00120 
•00135 
.00125 


Inch 
.0013 
.00160 


.00140 
.00110 


Inch 
.0015 
.00150 

•00135 
.00100 


Inch 
.00135 

.00105 


Inch 
.0015 


Average 
.00133 
.00143 
.00122 
.001235 
.00116 


General  average,  .001275  inch.  Corrected  average,  .001 175' inch. 


3l6  MODERN  DENTISTRY 

.      TABLE   II.— HARVARD   SPECIAL  Z 

Harvard  special  Z  =  Harvard  special,  under  loo  pounds  pressure,  one-quarter 
inch  glass,  i  minute,  released. 


Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.00140 

.00125 

•00155 

.00120 

.00150 

=    .00138 

.00120 

.00125 

.00125 

.00110 

.00125    ' 

=    .00121 

.00110 

.00115 

.00095 

.00120 

.00120 

=    .00112 

.00110 

.00110 

.00125 

.00130 

.00120 

=    .00121 

,00130 

.00120 

.00130 

■00135 

.00125 

=    .00128 

General  average,  .00124  inch.  Corrected  average,  .00114  inch. 

TABLE   12.— HARVARD   SPECIAL  Z' 
Harvard  special  Z'  =  Harvard  special,  100  pounds  pressure  until  set,  one- 
quarter  inch  glass. 


Inch 

Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.00095 

.00100 

.00125 

.00100 

.00095 

.001 

= 

.00102 

.00085 

.00100 

.00070 

.00090 

.00115 

= 

.00092 

.00110 

.00110 

.00098 

.00105 

.00080 

= 

.00101 

.00110 

.00085 

.00100 

.00105 

.0090 

= 

.00098 

.00110 

.0090 

.00100 

.00105 

.0090 

.00110 

= 

.00101 

Inch 

Inch 

.00015 

.0003 

.00035 

.00025 

.0003 

.00025 

General  average,  .00099  inch.  Corrected  average,  .00089  inch. 

TABLE   13.— HARVARD   PULVERIZED  W 

Harvard  pulverized  W  =  Harvard  pulverized  cement,  pressure  of  8  pounds 
maintained  until  setting  occurred.  Factor  of  error  due  to  water  film  not  present, 
as  the  measurements  were  made  on  adhesive  films,  the  cement  film  being  too  thin 
to  be  removed. 

Inch  Inch  Inch 

.00015         .0002  .00035 

.0002  -00035         .0003 

.00025         .0003  .0003 

General  average,  .00027  inch. 

Tests  of  the  Ames  inlay  cement  to  determine  the  thickness  of 
the  film  under  given  surfaces,  times,  and  pressures  were  as  follows : 

TABLE   14.— A-W 

Ames— W  =  one-quarter  inch  square  glass  at  8  pounds  pressure  for  i  minute ; 
one-eighth  inch  square  glass  at  2  pounds  for  i  minute. 

Water  fihn  that  floated  cement  on  face  plate  measured  o.oooi  inch.  Tehrefore, 
o.oooi  inch  should  be  subtracted  from  each  result  as  an  error  due  to  measuring  the 
water  film  with  the  cement  film. 


Inch 

Inch 

Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.00105 

.0011 

.00105 

.0012 

.001 

.00105 

= 

.00107 

.0014 

.0012 

.00115 

.0013 

.0015 

.0011 

.00125 

= 

.00127 

.0012 

.0012 

.00115 

.0013 

.0012 

= 

.00121 

.00115 

.0012 

.00115 

.00105 

.00105 

= 

.00112 

.0012 

.00125 

.0015 

.0013 

.0012 

= 

.00129 

General  average,  .00119 

inch. 

Corrected  average 

,  .00109 

inch. 

EXPERIMENTS    CONCERNING  VARIOUS   CEMENTS 


317 


TABLE  15— A-W 
Ames-W  =  one-quarter  inch  square  glass  at  8  pounds  pressure  for  15  minutes 
or  until  complete  setting  =  one-eighth  inch  square  glass  at  2  pounds  for  15  minutes 
or  until  set. 

Inch  Inch  Inch  Inch  Inch  Inch  Average 

.001  .00095         -ooi  -ooi  .00105         -ooi        =       -ooi 

.001  .0011  .00105         -ooi  .00105  =        .001  + 

.001  .001  .0011  .0012  .0012  =        .0011 

.00105         .00105         .0011  .0011  .00112  =        .ooii-|- 

.00112         .00112         .00112         .00112         .00112  =       .00112 

General  average,  .00106  inch. 
Corrected  average,  .00096  inch. 

TABLE   16.— A-X 
Ames-X  =  one-quarter  inch  square  glass,  25  pounds  pressure  for  i  minute 
released,  and  allowed  to  harden. 

Inch 
.001 
.00095 
.00095 
.0011 
.001 

General  average,  .000986  inch. 
Corrected  average,  .000886  inch. 

TABLE   17.— A-X' 
Ames-X'  =  one-quarter  inch  square  glass,  25  pounds  continuous  pressure 
until  hard. 

Inch  Inch  Inch  Inch 

.00085         .0009  .0009  .0009 

.00085         .0009  .00105         .0011 

.0012  .001  .0014  .0012 

.00095         .00082         .001  .0011 

.0009  .001  .0009  .0011 

General  average,  .000982  inch. 
Corrected  average,  .000882  inch. 

TABLE   18.— A-Y 
Ames— Y  =  one-quarter  inch  square  glass,  50  pounds  pressure  for  i  minute, 
released,  and  allowed  to  harden. 


Inch 

Inch 

Inch 

.001 

.001 

.001 -|- 

.00105 

.0085 

.0009 

.00095 

.001 

.0011 

.00085 

.0009 

.00105 

.00095 

.001 

.00105 

Inch 

Average 

.00105 

= 

.00101 

.001 

= 

.00095 

.001 

= 

.001 

.001 

= 

.00098 

.00095 

= 

.00099 

Inch 

Inch 

Average 

.0009 

=  .00089 

.001 

=  .00098 

00095 

.00103 

=  .00113 

.00085 

=  .00094 

.00095 

=  .00097 

Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.00075 

.0008 

.00085 

.00075 

.00085 

=    .0008 

.0008 

.00095 

.00085 

.00085 

.0009 

=    .00085 

.0009 

.00085 

.0008 

.00088 

.00085 

=    .000856 

.0008 

.0008 

.0009 

.00095 

.00085 

=    .00086 

.00065 

.00075 

.0008 

.00075 

.00085 

=    .00076 

General  average,  .000825  inch. 
Corrected  average,  .000725  inch. 


3i8 


MODERN  DENTISTRY 


TABLE   19.— A-Y' 


Ames-Y'  =  one-quarter  inch  square  glass,  50  pounds  continuous  pressure 


until  hard. 

Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.0008 

.00075 

.00082 

.00082 

.00085 

= 

.000808 

.0008 

.00075 

.00077 

.00072 

.00069 

= 

.000746 

.00095 

.00085 

.0007 

.0008 

.0008 

= 

.00082 

.001 

.00085 

.00075 

.00085 

.001 

= 

.00089 

.0007 

.00085 

.0007 

.0008 

.0007 

= 

.00075 

General  average,  .000802  inch. 
Corrected  average,  .000702  inch. 


TABLE  20.—. 

\-Z 

Ames-Z  = 

one-quarter 

inch  square  glass, 

100  pounds 

pressure  for  i  minute, 

released,  and  allowed  to  harden. 

Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.00085 

.00085 

.00095 

.0009 

.00005 

= 

.00093 

.00085 

.0007 

.00095 

.0007 

.00075 

= 

.00079 

.00095 

.00085 

.0007 

.0008 

.0008 

= 

.00082 

.001 

.00085 

.00075 

.00085 

.001 

= 

.00089 

.0011 

.001 

.00095 

.00095 

.0011 

= 

.00102 

General  average,  .00089  inch. 
Corrected  average,  .00079  inch. 


TABLE   21.— A-Z' 


Ames-Z'  =  one-quarter  inch  square  glass,  100  pounds  pressure  until  hard. 


Inch  Inch  Inch  Inch 

.0008  .00082        .00075        .0007 

.00065        .00075        .0007  .0006 

.00075        .00065        .0008  .0007 

.00061        .00073        .00061        .0006 
.0006  .00065        .00065        .00085 

General  average,  .000704  inch. 
Corrected  average,  .000604  inch. 


Inch 

Inch 

Average 

.0008 

.0007 

=  .00076 

.0008 

.00085 

=  .000725 

.00065 

=  .00071 

.00062 

=  .000634 

.00075 

=  .00007 

TABLE  22.— ASH  W 

Ash  W  =  Ash  common  phosphate  of  zinc  cement,  8  pounds  pressure,  one- 
quarter  inch  square  glass,  for  i  minute,  and  released. 


Inch 

Inch 

Inch 

Inch 

Inch 

Average 

.0021 

.00215 

.00195 

.00195 

.00212 

= 

.00206 

.0022 

.0023 

.0024 

.00233 

.00235 

= 

.00230 

.00231 

.00230 

.00230 

.00230 

.00230 

= 

.00230 

.00215 

.0029 

.00265 

.00210 

.00220 

= 

.0024 

.00280 

.0029 

.00290 

.00310 

.00280 

= 

.0029 

General  average,  .00239  inch. 
Corrected  average,  .00229  inch. 


EXPERIMENTS   CONCERNING  VARIOUS   CEMENTS 


319 


Comparisons  are  given  of  corrected  general  averages  of  cement 
lines  made  under  8  pounds  pressure.  W  =  released  after  i 
minute.  W  =  pressure  maintained  until  setting  is  complete. 
Except  in  Harvard  pulverized,  which  was  measured  adhering  to 
glass,  o.oooi  inch  was  subtracted  from  each  as  a  factor  of  error. 

Harvard  coarse  W 00243  i^^ch 

Harvard  coarse  W 00249  inch 

Harvard  inlay  W 00168  inch 

Harvard  inlay  W 00171  inch 

Harvard  special  W 00156  inch 

Harvard  special  W 00152  inch 

Harvard  pulverized 00027  i^^ch 

Ash  W .00229  iiich 

Ames-W 00109  i^ch 

Ames-W 00096  inch 

X  =   25  pounds  pressure  one-quarter  inch  square  glass  for  i 
minute,  then  released. 

X'  =   25  pounds  pressure  one-quarter  inch  square  glass  until 
complete  setting  occurs. 

Y  =   50  pounds  pressure  one-quarter  inch  square  glass  for 
I  minute,  then  released. 

Y'  =   50  pounds  pressure  one-quarter  inch  square  glass  until 
setting  occurs. 

Z   =   100  pounds  pressure  one-quarter  inch  square  glass  for 
I  minute,  then  released. 

Z'   =   100  pounds  pressure  one-quarter  inch  square  glass 
until  setting  occurs. 

H   =  Dr.  Head's  special  Harvard. 
A  =  Ames  Inlay  Cement. 

Comparison  of  corrected  general  averages  between  the  Har- 
vard special  and  the  Ames  cements : 


H  X  =  .00143  inch 

AX  = 

.000886  inch 

HX'  =  .00125  " 

AX'  = 

.000882  " 

HY  =  .00106  " 

AY  = 

.000725  " 

HY'  =  .00118  " 

AY'  = 

.000702  " 

HZ  =  .00114  " 

AZ  = 

.00079   " 

HZ'  =  .00089  " 

AZ'  = 

.000604  " 

320 


MODERN  DENTISTRY 


Having  discussed  the  fineness  of  cement  lines  and  having 
arrived  at  the  conclusion  that  the  fine  cement  line  is  due  to  the 
fineness  of  the  cement  powder,  rather  than  to  the  amount  of  pres- 
sure applied  or  to  the  length  of  time  the  pressure  is  maintained, 
let  us  take  up  the  question  of  strength  and  adhesion.  As  before 
stated,  the  Harvard  cements  and  the  Ames' inlay  cement  were 
the  only  ones  investigated  at  length.  Of  Harvard,  the  coarse 
and  the  pulverized  were  used  as  two  extremes  to  show  which  gave 
the  most  strength  and  the  greatest  adhesion. 

Adhesion  of  Cement. — The  first  adhesion  tests  were  made 
with  the  glass  squares  etched  with  hydrofluoric  acid.  Pieces 
j-inch  square  were  cemented  to  pieces  |-inch  square  under  8 
pounds  pressure  for  fifteen  minutes,  and  set  in  water  over  night. 
Two  specimens  of  Harvard  coarse,  three  of  Harvard  pulverized, 
and  two  of  the  Ames  inlay  were  thus  prepared.  In  the  morning 
the  glasses  all  fell  apart.  This  result  showed  that  the  expansion 
and  contraction  of  the  glass  was  sufficient  to  tear  it  loose  from 
the  cement.  At  first  it  was  thought  the  tests  would  have  to  be 
made  in  a  culture  oven  at  a  temperature  of  98°  F.,  the  normal 
temperature  of  the  mouth ;  but  tests  with  a  cHnical  thermometer 
in  the  mouth  after  eating  hot  soup  at  152°  F.  showed  that  the 
mouth  could  by  this  means  be  raised  to  a  temperature  of  108°  F. 
This  demonstrated  that  experiments  made  in  an  even  temperature 
would  not  be  fair,  as  it  was  apparent  that  a  filling  might  be  sub- 
jected to  hot  soup  at  a  temperature  of  152°  F.  and  ice  cream  at  a 
temperature  of  32°  F.,  a  variation  of  120  degrees.  Therefore,  for 
the  adhesion  tests  glass  was  discarded  and  pieces  of  porcelain 
|-inch  square  and  rS'-inch  thick,  perfectly  flat,  were  cemented  to 
a  block  of  ivory  that  had  been  draw-filed  flat  and  smooth.  In  all 
of  these  tests  the  porcelain  and  ivory  were  washed  with  alcohol 
and  dried  before  they  were  cemented  together.  In  the  tests 
where  the  porcelain  was  only  ground  with  a  wheel  the  results 
were  so  discouraging  that  they  will  only  be  summarized.  The 
porcelain  pieces  were  carefully  ground  so  as  to  be  the  same  size 
in  order  that  a  just  comparison  could  be  obtained. 

A  number  of  tests  were  made  under  8  pounds  pressure  and 
thumb  pressure  until  setting  was  complete,  and  some  under 


EXPERIMENTS    CONCERNING  VARIOUS   CEMENTS  32 1 

thumb  pressure  for  a  minute,  and  then  released.  The  Harvard 
cement  was  paraffined  before  being  placed  in  water.  The  Ames 
cement  was  not  paraffined,  as  the  Ames  cement  set  better  when 
exposed  to  water.  The  following  morning  the  pieces  of  ivory 
and  porcelain  were  removed  from  the  water,  dried  with  a  cloth, 
and  the  paraffin  and  cement  carefully  cleansed  from  the  edges. 
The  ivory  block  was  then  placed  in  a  vise  and  the  pieces  of  porce- 
lain pulled  off  sideways  with  the  hook  of  a  spring  balance  scale. 
Before  each  test  the  face  of  the  scale  was  blackened  in  a  gas  jet 
so  that  the  indicator  would  mark  the  highest  mark  reached  as 
the  cement  broke  and  the  pointer  flew  back.  These  same  spring 
scales  were  arranged  with  nails  and  board  so  that  they  could  be 
used  to  maintain  the  required  pressure  on  the  cement  films  as 
they  were  setting.  The  results  were  so  insignificant,  there  being 
practically  no  difference  between  the  maintained  pressure,  the 
temporary  pressure,  the  8  pounds  pressure,  and  the  4  pounds 
or  thumb  pressure,  that  for  the  plain,  ground  porcelain  surfaces 
only  those  made  under  thumb  pressure,  released  after  one  minute, 
and  then  set  in  water  over  night  will  be  quoted.  The  tests  made 
with  the  Harvard  coarse  gave  a  breaking  strain  of  the  following 
figures:  3,  5,  14,  19,  21,  13,  27,  28,  34,  42  ounces — an  average 
of  20  ounces.  Harvard  pulverized  gave  the  following  figures: 
10,  10,  16,  8,  31,  35,  II,  16,  54,  32  ounces— an  average  of  22 
ounces.  The  Ames  cement  under  similar  conditions  gave: 
o,  o,  64,  20,  10,  6,  o,  o,  10,  32  ounces — an  average  of  14  ounces. 
These  roughly  show  a  slight  superiority  of  adhesion  for  the 
pulverized  Harvard,  but  the  result  is  not  sufficiently  conclusive 
to  be  of  great  value.  It  certainly  shows  that  the  adhesion  of 
cement  to  ground  porcelain  and  to  flat,  smooth  ivory  is  slight 
and  unreliable.  In  these  tests  the  cement  film  seemed  to  break 
away  equally  from  the  porcelain  and  ivory. 

Having  proved  that  draw-filed  ivory  and  ground  porcelain 
have  very  little  adhesion  to  cement,  the  pieces  of  porcelain  were 
etched  for  thirty  seconds  with  hydrofluoric  acid,  washed  thor- 
oughly with  water,  dried,  washed  in  alcohol,  and  dried  again. 
The  blocks  of  ivory  were  simply  given  the  ordinary  soaking  in 
water  to  make  them  as  much  like  the  tooth  structure  as  possible, 


322  MODERN  DENTISTRY 

wiped  dry  with  a  cloth,  the  surfaces  washed  with  alcohol,  and 
dried  with  the  air-blast.  Because  the  etching  with  hydrofluoric 
acid  had  caused  so  little  adhesion  of  the  cement  to  the  glass, 
I  had  doubts  as  to  whether  it  would  cause  adhesion  to  a  flat 
surface  of  porcelain.  Roughening  the  surface  of  a  deep  porce- 
lain filling  would  obviously  act  as  small  undercuts  and  cause 
the  cement  to  retain  the  filling,  but  there  was  much  doubt  in 
my  mind  concerning  the  power  of  etching  to  cause  adhesion 
of  cement  to  a  flat  surface. 

Six  preliminary  tests  were  made  with  the  ^-inch  square  of 
etched  porcelain  cemented  to  the  ivory  blocks  under  8  pounds 
pressure  for  one  minute  and  then  released,  two  with  Harvard 
coarse,  two  with  Harvard  pulverized,  and  two  with  the  Ames 
inlay.  Next  morning  the  four  Harvard  cement  films  tore  away 
from  the  ivory  at  about  a  67-ounce  pull,  remaining  firmly  ad- 
herent to  the  porcelain,  while  the  Ames  cement  dropped  off  the 
ivory  with  a  pull  too  small  to  be  measured.  This  seemed  to  give 
a  maximum  adhesion  of  the  Harvard  cement  to  a  plain  ivory 
|-inch  square  of  a  little  over  4  pounds. 

It  was  then  seen  that  if  the  adhesion  of  cement  to  etched 
porcelain  was  to  be  measured,  some  way  would  have  to  be 
devised  to  make  the  cement  stick  more  securely  to  the  ivory. 
This  was  done  by  making  deep  undercuts  in  the  ivory.  These 
undercuts  were  filled  with  the  cement  and  the  pieces  of  etched 
porcelain  pressed  upon  the  overflowing  cement,  kept  under  8 
pounds  pressure  for  one  minute,  and  then  released  and  treated 
in  the  usual  way.  Next  morning,  when  these  pieces  of  porcelain 
were  pulled  off,  the  two  etched  squares  of  porcelain  broke  loose 
from  the  Harvard  coarse  cement  at  16  pounds  and  22  pounds 
each.  The  Ames  broke  at  6  pounds  and  3  pounds  each.  In 
each  test  there  was  clean  tearing  away  of  the  porcelain  from  the 
cement.  The  next  tests  were  identical  with  those  just  described, 
only  the  old  cement  in  the  undercuts  was  simply  filed  smooth, 
and  the  cleansed  porcelain  squares  cemented  under  8  pounds 
pressure  for  one  minute  to  the  old  cement  and  the  adjacent 
ivory  that  had  simply  been  washed  with  alcohol  and  dried. 
Further   tests  proved  that  the  fresh   cement  would   stick  to 


EXPERIMENTS    CONCERNING  VARIOUS   CEMENTS 


323 


the  old  cement  more  firmly  than  it  would  stick  to  the  etched 
porcelain. 

The  following  tables  and  their  general  averages  tell  their 
own  story.     Tests,  as  previously  stated,  were  made  under  8 
pounds  pres.ure  for  one  minute.    These  same  tests  were  dupli- 
cated with  the  8  pounds  pressure  maintained  until  setting  was 
complete.     Harvard  coarse,  under  8  pounds  pressure  for  one 
minute,  released,  paraffined,  set  in  water  over  night  and  pulled 
off  in  the  morning,  showed  that  etched  porcelain  broke  away 
from  undercut  ivoiy  at  16,  22,  16,  12,  11,  13,  15,  20,  16,  11,  12, 
14,  14,  i4>  16,  12,  15,  10  pounds.     General  average  13  pounds, 
2  ounces,  to  i-inch  square  surface.     When  the  pressure  was 
maintained    until    setting    cccurred,   the    breaking  strain  was 
found  to  give  the  following  figures:  6,  16,  13,  10,  12,  18,  13,  4, 
10,  8,  9  pounds,  giving  a  general  average  of  11  pounds,  10  ounces. 
This  shows  that  with  Harvard  coarse  maintaining  the  pressure 
did  not  increase  the  adhesion.     These  same  tests  were  made 
with  Harvard  pulverized.     Where  the  8  pound  pressure  was 
maintained  for  one  mmute  only,  we  have  the  following  figures: 
12,  12,  13,  8,  9,  13,  18,  21  pounds,  giving  a  general  average  of 
13  pounds,  4  ounces.     Where  pressure  was  maintained  until 
setting  was  complete,  the  following  were  the  figures:  16,  12,  25, 
24,  28,  17,  14,  13,  giving  a  general  average  of  17  pounds,  7  ounces. 
With  the  Ames  cement,  where  8  pounds  pressure  was  maintained 
for  one  minute,  the  following  figures  were  obtained:  6,  3,  13,  13,  o, 
i7>  iij  3  pounds,  giving  a  general  average  of  8  pounds,  4  ounces. 
Where  the  pressure  was  maintained  until  setting  occurred  the 
Ames  cement  gave  the  following  figures:  6,  8,  6,  7,  14,  16,  12,  11, 
iij  i3>  12,  9,  8,  10,  7,  8,  7  pounds,  giving  a  general  average  of 
9  pounds,  9  ounces. 

Summary. — General  average  for  8  pounds  pressure  for  one 
minute  only;  ivory  undercut,  porcelain  etched: 
Harvard  coarse,  13  lbs.,  2  oz. 
Harvard  pulverized,  13  lbs.,  4  oz. 
Ames  inlay,  8  lbs.,  4  oz. 
Average,  11  pounds,  8  ounces. 


324  MODERN  DENTISTRY 

General  average  for  8  pounds  pressure  until  setting  is  com- 
plete : 

Harvard  coarse,  ii  lbs.,  lo  oz. 

Harvard  pulverized,  17  lbs.,  7  oz. 

Ames  inlay,  9  lbs.,  9  oz. 
Average,  12  pounds,  14  ounces. 
The  fact  that  the  Harvard  coarse  cement  does  not  show 
greater  stress-bearing  power  when  the  pressure  was  maintained 
until  complete  setting  is  possibly  explained  by  the  fact  that  with 
coarse  powder  sometimes  a  particle  might  be  so  large  as  to  pre- 
vent general  pressure.  Certainly  with  the  Harvard  cement  it  is 
clear  that  the  finer  the  powder,  the  stronger  the  adhesion  and  the 
finer  and  truer  the  film.  These  tests  also  show  that  new  cement 
will  stick  firmly  to  old  cement;  that  a  thin  film  does  not  seem 
to  be  as  strong  as  a  thick  film;  that  ground  porcelain  and  rough- 
ened ivory  have  little  adhesive  power,  while  etched  porcelain 
has  great  power  of  adhesion  to  cement.  This  seems  at  first  an 
anomaly,  since  etching  with  hydrofluoric  acid  has  no  such  power 
on  glass,  but  a  little  thought  will  solve  the  difficulty.  Glass  is  a 
homogeneous  substance,  and  etches  smoothly  and  homogeneously, 
but  porcelain,  being  composed  of  quartz,  feldspar,  and  flux, 
etches  unevenly  in  pits  and  undercuts. 

The  fact  that  the  old  cement  will  adhere  to  the  new  cement 
more  firmly  than  the  new  cement  will  adhere  to  the  etched 
porcelain,  makes  it  feasible  to  fill  undercut  cavities  with  cement 
until  setting  occurs,  and  then  to  cut  out  of  the  cement  a  simple 
cavity  with  clean  enamel  edges.  Thus  may  a  difiicult  filHng 
be  converted  into  a  simple  filling. 

Numerous  tests  were  made  with  the  flat  porcelain  on  which 
zinc  oxid  had  been  fused  to  see  if  such  porcelain  had  greater 
adhesion  to  the  cement  than  etched  porcelain.  When  zinc  oxid 
was  given  just  the  right  fusion,  |-inch  square  of  porcelain  with 
Harvard  pulverized  stood  as  high  as  30  pounds  pressure,  but 
later  fusions  of  zinc  oxid  to  the  porcelain,  made  with  equal  care, 
gave  sometimes  no  adhesion  at  all,  or  only  2  or  3  pounds.  There- 
fore, although  at  first  it  was  thought  that  the  principle  of  par- 
tially fusing  zinc  oxid  to  the  porcelain  filling  for  purposes  of 


EXPERIMENTS   CONCERNING  VARIOUS   CEMENTS 


325 


adhesion  might  prove  of  value,  its  unreHabihty  finally  forced 
the  conclusion  that  etching  with  hydrofluoric  acid  is  more  feas- 
ible and  trustworthy. 

In  order  to  verify  the  accuracy  of 
these  data  it  was  decided  to  insert  a 
series  of  ten  porcelain  fillings  of  stand- 
ard size  in  a  piece  of  ivory,  and  after 
they  had  been  cemented  into  position 
imder  various  conditions  with  the  Ames 
and  Harvard  pulverized  cements  respec- 
tively, to  push  the  fillings  out  of  the 
cavities  with  a  plunger  inserted  from 
below  and  attached  to  a  scale. 

The  cavities  were  made  and  reamed 
to  standard  size — 0.3125  inch  in  diam- 
eter at  the  top,  0.125-inch  deep,  and 
0,187-inch  in  diameter  at  the  bottom. 
Holes  about  0.031-inch  in  diameter 
were  carefully  bored  in  the  bottom  of 
each  cavity  through  the  piece  of  ivory 
to  make  easy  passage  for  the  plunger. 
The  porcelain  fiUings  were  made  with 
the  platinum  matrices  in  the  usual 
way,  the  holes  in  the  bottom  of  the 
cavities  being  temporarily  stopped  with 
wooden  plugs.  The  plunger  was  ce- 
mented into  the  inside  of  a  celluloid 
ring  attached  to  a  spring  balance. 
Thus,  by  inserting  the  plunger  in  the 
holes  under  the  fillings,  pressure  against 
the  fillings  was  obtained  by  a  pull  on 
the  spring  (Fig.  279).  When  the  pres- 
sure tests  were  to  be  made  the  block 

of  ivory  containing  the  cemented  inlays  was  placed  upright  in 
a  vise.  The  ring  containing  the  plunger  was  sHpped  over  it  and 
the  plunger  inserted  in  the  hole  beneath  the  fiUing  to  be  tested; 
then  the  spring  was  steadily  pulled  and  pressure  made  until 


Fig.  279. — Machine  for 
measuring  force  reqmred  to 
push  out  a  cemented  porce- 
lain inlay:  A,  ivory  block 
with  inlay  cemented  into 
position  as  shown;  B, 
ivory  ring  fitted  with  a 
plunger  that  is  inserted 
into  a  hole  beneath  each 
filling.  Pressure  is  applied 
and  measured  by  spring 
balance 


326  MODERN  DENTISTRY 

the  filling  was  loosened.  The  exact  pressure  reached  at  the  giving 
way  of  the  fillings  was  measured  by  the  needle  marking  a  carbon 
film  on  the  scale,  as  described  previously  in  the  other  adhesion 
tests. 

The  first  two  tests  were  to  obtain  the  adhesion  of  perfectly 
smooth  ivory  walls  to  smooth,  glazed,  closely  fitting  porcelain. 
These  filHngs  were  cemented  into  place  with  pulverized  Harvard 
cement  at  thumb  pressure  for  one  minute  and  then  allowed  to  set, 
care  being  taken  to  remove  all  superfluous  cement  in  the  holes 
under  the  fillings,  so  that  there  would  be  free  movement  and 
apposition  of  the  plunger  against  the  porcelain.  The  filhngs 
were  then  paraffined  and  placed  in  water  over  night.  In  the 
morning  not  one  of  these  fillings  stood  a  pressure  of  8  ounces, 
and  most  of  them  came  out  with  very  much  less.  The  fillings 
and  cavities  were  then  carefully  cleansed  of  cement  with  dilute 
sulphuric  acid  and  washed  in  alcohol  and  dried.  The  filhngs 
were  then  recemented  into  position  with  the  Ames  inlay  cement 
with  a  similar  result — no  filHng  stood  more  than  8  ounces,  and 
most  came  out  with  a  pressure  of  2  or  3  ounces.  These  tests 
proved  that  plain  ivory  surfaces  in  apposition  with  glazed  porce- 
lain with  a  thin  film  of  cement  did  not  make  a  satisfactory  union. 

The  next  two  tests  were  made  under  exactly  similar  conditions, 
except  that  the  fillings  were  etched  with  hydrofluoric  acid  for 
thirty  seconds.  The  walls  of  the  cavities  were  smooth  and  with- 
out undercuts.  The  following  results  were  obtained :  Harvard 
pulverized,  37,  28,  47,  96,  20,  30,  34,  66,  88  ounces  respectively, 
average  3  pounds,  3  ounces.  Ames  inlay,  40,  40,  32,  57,  90,  64, 
39}  33)  385  37  ounces  respectively,  average,  2  pounds,  12  ounces. 

In  the  next  tests  the  cavities  instead  of  being  smooth,  with 
sloping  walls,  were  deeply  undercut:  Harvard  pulverized,  8|, 
9,  II,  15!,  7,  6,  13,  14  and  18  pounds  respectively,  average  11 
pounds,  6  ounces.  Ames  inlay,  14,  10,  13I,  7I  7,  17,  11,  13,  and 
17I  pounds  respectively,  average,  12  pounds,  10  ounces. 

In  the  final  tests  the  fillings  were  deeply  midercut,  resembling 
small  coUar  buttons,  without  the  slightest  attempt  being  made 
to  fit  the  cavity  except  at  the  margin,  and  the  cavities  were  more 
deeply  undercut, -to  make  as  great  a  cement  mass  around  the 


EXPERIMENTS   CONCERNING  VARIOUS   CEMENTS 


327 


filling  as  possible.  The  results  were  as  follows:  Harvard  pul- 
verized, 32,  25,  24,  23,  20,  18,  28,  30,  and  27  pounds  respectively, 
average,  25  pounds,  7  ounces.  Ames  inlay,  18,  20,  17I,  loj, 
172,  33}  26,  and  21  pounds  respectively,  average,  19  pounds. 

Conclusions  on  Cement  as  an  Inlay  Bond.— These  tests  and 
tables  indicate:    (i)    Glazed  or  ground  porcelam  and  smooth 
ivory  have  but  little  power  of  adhesion  for  cement.    (2)   A  thin 
film  of  cement  is  not  so  strong  a  bond  as  a  thick  mass.    (3)   The 
edges  of  a  filHng  should  be  in  as  close  apposition  as  possible, 
but  wherever  feasible  the  cement  that  holds  the  filKng  m  the 
cavity  should  have  body  and  act  as  a  dowel.     (4)    Etching  of 
porcelain  with  hydrofluoric  acid  is  a  valuable  means  of  obtaining 
adhesion  where  the  filHng  is  too  shallow  for  undercuts;  but 
undercuts  are  to  be  preferred  where  they  can  be  obtained,  and 
there  is  good  reason  to  beheve  that  the  best  results  are  gained 
by  both  undercutting  and  etching  the  filHng.    (5)   Fusion  of  zmc 
oxid  to  the  porcelain  inlay  for  adhesion  purposes  is  unreliable. 
(6)   Fineness  of  grit  in  a  cement  is  more  responsible  for  a  fine 
cement  line  than  pressure.     (7)    Reduction  of  the  cement  grit 
adds  to  the  strength  and  power  of  adhesion.    This  is  a  law  that 
appHes  to  aU  cements  if  they  are  not  thereby  made  to  set  too 
quickly.     (8)   With  Harvard  pulverized  cement,  maintaining 
the  pressure  during  the   complete  process  of  setting  sHghtly 
diminishes  the  cement  line  and  increases  the  adhesion  24  per 
cent.     (9)   Where  the  mlay  and  cavity  are  sufficiently  deep  to 
allow  the  final  expansion  characteristic  of  the  Harvard  cement 
during  crystaUization  to  be  exerted  on  the  filHng  and  cavity, 
maintaining  the  pressure  is  only  valuable  for  the  sake  of  apposi- 
tion, as  more  pressure  is  probably  obtained  by  the  crystalHzation 
of  the  cement  than  can  be  exerted  by  external  pressure. 

These  tests  were  made  ten  years  ago,  and  suice  that  time 
Dr.  Ames  has  done  magnificent  work  in  evolving  cements  that 
are  of  incalculable  value  to  the  profession,  and  that  have  now 
largely  replaced  the  earlier  cements. 

Solubility  of  Cement  Line. — When  I  started  to  put  in  inlays 
I  beHeved  that  an  accurately  fitting  inlay  with  a  so-called  perfect 
edge  and  microscopic  line  of  phosphate  of  zinc  cement  would 


328  MODERN  DENTISTRY 

preserve  its  integrity  in  any  mouth  where  there  was  proper 
hygienic  care.  I  believed  that  the  mucin  of  the  saliva  acting 
as  a  plug  in  a  fine  hne  would  stop  osmosis  of  any  neighboring 
solvent  and  prevent  continued  deterioration,  and  that  a  coarse 
Une  would  not  have  any  such  preservative  effect,  as  here  the 
mucin  would  be  constantly  changed  and  washed  away.  I  also 
held  that  the  more  perfectly  the  inlay  fitted  the  cavity  and  the 
less  room  there  was  for  cement,  the  greater  would  be  the  security 
against  dislodgment.  Since  that  time  I  have  noticed  that  in 
some  mouths  a  certain  percentage  of  inlays  with  perfect  adapta- 
tion will  show  undoubted  signs  of  discoloration  and  disintegra- 
tion at  their  margins,  and  that  the  Httle  shallow  labial  cavities 
that  allow  only  a  thin  cement  film  for  retention  are  the  inlays 
most  likely  to  drop  out. 

I  decided,  therefore,  to  undertake  experiments  to  determine 
the  relative  solubility  of  thick  and  thin  lines  of  cement.  In 
preparation  for  these  tests  pieces  of  plain  glass  were  etched 
with  hydrofluoric  acid,  then  creamy  cement  was  firmly  pressed 
between  them  and  allowed  to  set  for  fifteen  minutes.  These 
pieces  of  glass  and  cement  were  then  placed  in  water  and  at  the 
end  of  twenty-four  hours  the  glasses  fell  apart,  leaving  free 
cement  films.  What  was  desired  was  glass  so  etched  that  it 
would  permanently  adhere  to  the  cement,  in  order  that  the  action 
of  solvent  fluids  could  be  studied  on  a  cement  film  protected 
as  at  the  margins  of  an  inlay.  Finally,  after  many  experiments 
it  was  found  that  the  fumes  of  hydrofluoric  acid  would  occasion- 
ally form  an  undercut  etch  on  glass  sufiicient  to  cause  wet 
cement  to  permanently  adhere  to  the  glass,  and  in  such  cases 
the  glass  was  carefully  preserved  and  cut  up  into  l-inch  squares. 
Agate  etched  with  liquid  hydrofluoric  acid  was  found  to  give 
permanent  hold  to  wet  cement.  Therefore,  the  J-inch  squares 
of  glass  were  cemented  to  the  etched  agate  and  the  edges  care- 
fully cleaned.  Thus  the  corroding  action  of  the  various  solvents 
on  the  cement  films  could  be  noted,  being  discernible  through 
the  glass  with  the  dark  agate  as  a  background. 

Having  solved  the  problem  of  making  cement  stick  to  glass 
when  immersed  in  an  aqueous  solution,  the  next  question  was 


EXPERIMENTS   CONCERNING  VARIOUS   CEMENTS  329 

to  decide  on  the  fluids  with  which  to  carry  on  the  tests.  Free 
films  of  cement  and  tooth  enamel  were  placed  in  various  solvents 
such  as  acetic,  valeric,  butyric,  citric,  and  lactic  acids  and  c.  p. 
ammonium  hydrate  (28  per  cent.),  all  of  which  reagents  have  been 
detected  in  a  diluted  form  in  the  human  sahva.  Their  effect 
was  primarily  tried  on  natural  tooth  enamel,  because  it  was 
considered  that  fair  tests  on  the  solvency  of  protected  cement 
could  only  be  made  with  fluids  that  would  not  dissolve  tooth 
enamel  more  rapidly  than  cement,  nor,  in  fact,  dissolve  enamel 
at  all,  as  only  such  solvents  would  approximate  the  conditions 
found  around  inlays  in  the  mouth.  Natural  tooth  enamel  and 
thin  unprotected  pieces  of  Harvard  cement  were  tested  simul- 
taneously in  solutions  of  various  strengths  of  the  solvents  just 
mentioned.  For  instance,  a  tooth  and  cement  film  when  placed 
in  28  per  cent,  aqua  ammonia  showed  rapid  dissolution  of  the 
cement  with  practically  no  harm  to  the  enamel.  When,  how- 
ever, the  ammonia  was  reduced  to  2  or  i  per  cent,  it  ren- 
dered the  cement  film  only  shghtly  defective  in  the  course  of 
some  days,  and  when  a  film  of  cement  protected  on  each  side 
by  glass  and  agate  was  placed  in  such  an  aqueous  solution  of 
ammonia,  the  power  of  osmosis  seemed  incapable  of  either 
weakening  or  dissolving  the  cement  during  a  period  of  months. 
Therefore,  ammonia  in  any  strength  that  could  possibly  exist 
in  the  mouth  was  found  to  be  harmless  to  the  cement  fine.  When, 
however,  lactic,  valeric,  butyric,  and  acetic  acids  were  tested,  a 
conclusion  was  not  so  readily  reached.  Anhydrous  c.  p.  lactic, 
valeric,  and  butyric  acids  had,  as  would  be  expected,  no  dis- 
cernible effect  on  tooth  enamel,  and  Httle,  if  any,  on  cement, 
except  in  the  case  of  valeric  acid,  which  made  the  free  cement 
film  defective.  But  when  these  acids,  as  well  as  acetic  and  citric 
acids,  were  tested  in  aqueous  solutions  of  from  i  to  o.i  per 
cent.,  or  even  0.05  per  cent.,  the  action  on  tooth  enamel  was 
terrific.  For  instance,  i  per  cent,  aqueous  solutions  of  lactic, 
acetic,  or  citric  acids  would  roughen  enamel  in  three  minutes; 
in  ten  minutes  a  chalky  surface  appeared,  and  in  twenty-four 
hours  all  enamel  was  practically  eaten  away.  Valeric  and  butyric 
acids  in  i  per  cent,  solutions  did  not  seem  to  materially  hurt 


33°  MODERN  DENTISTRY 

enamel  during  twenty-four  hours,  but  at  the  end  of  three  months 
they  had  made  deep  holes  in  the  dentin — a  clean  scoop  with  no 
leathery  dentin  remaining.  These  acids,  it  is  true,  affected 
cement  fihns  in  various  degrees,  but  by  comparison  with  their 
action  on  enamel  the  cement  was  practically  permanent,  and  it 
was  apparent  that  if  we  could  find  a  cement  that  would  last  in 
the  mouth  as  much  longer  than  the  enamel,  as  the  film  of  cement 
outlasted  the  enamel  in  these  aqueous  solutions,  we  would  have 
a  cement  that  would  in  ordinary  circumstances  last  many  times 
a  man's  lifetime.  But  these  results  were  preposterous,  since 
ordinarily  in  the  mouth  the  enamel  remained  while  the  cement 
dissolved.  Proceeding  with  the  experiments  with  aqueous 
solutions  and  taking  lactic  acid  as  a  basis,  teeth  were  tested  in 
I  :  20,000  lactic  acid  and  water  and  it  was  found  in  three  days  that 
the  enamel  was  softened  to  the  cut  of  a  lancet,  giving  a  cheesy, 
colloid  shaving.  And  yet  it  must  be  understood  that  this  amount 
of  acid,  powerful  as  it  was,  was  so  minute  as  to  be  hardly  per- 
ceptible to  any  chemical  tests.  At  last,  after  carrying  on  innumer- 
able tests  with  solutions  at  blood  temperature,  it  was  found  that 
the  source  of  error  lay  in  the  use  of  aqueous  solutions,  and  that 
saHva  solutions  should  be  used  if  results  approximating  those 
found  in  the  mouth  were  to  be  obtained. 

For  instance,  a  solution  i  :  500  of  lactic  acid  and  one  saliva 
tested,  although  it  turned  blue  litmus-paper  brilHantly  red  and 
had  a  sharp  acid  taste,  preserved  enamel  for  days  or  even  weeks 
unharmed.  At  other  times  this  same  person's  saliva  in  lactic 
acid  solutions  of  from  i  :  800  to  i  :  1000  would  not  be  able  to  pro- 
tect enamel  from  decalcification  for  any  length  of  time.  It  was 
also  discovered  that  in  saliva  solutions  the  cement  was  less 
protected  from  acid  disintegration  than  was  the  enamel;  it  was 
noted,  too,  that  some  saHvas  were  much  better  protectives  for 
cement  than  others.  For  instance,  a  i  :  1000  solution  of  lactic 
acid  and  one  saliva  would  steadily  dissolve  cement,  while  it 
would  not  dissolve  enamel.  A  i  :  500  lactic  acid  solution  with 
another  sahva  would  protect  both  enamel  and  cement;  and  as 
an  interesting  fact  it  might  be  mentioned  that  cement  lasts 
extremely  well  in  the  mouth  from  which  this  latter  saliva  was 


EXPERIMENTS   CONCERNING  VARIOUS   CEMENTS  33 1 

derived.  So  the  problem  of  what  fluids  to  use  in  these  cement- 
dissolving  tests  was  solved  by  using  saliva  solutions  of  lactic 
acid.  Lactic  acid  was  chosen  not  because  acetic,  citric,  butyric, 
and  valeric  acids  might  not  also  attack  the  cement  in  the  mouth, 
but  because  its  action  in  these  tests  more  nearly  represented 
the  kind  of  decalcification  which  the  author  had  noted  in  the 
mouth.  Valeric  and  butyric  acids  slightly  attack  cement,  while 
acetic  and  citric  acids  attack  it  quite  vigorously,  and  it  is  quite 
possible  that  these  acids  are  responsible  for  the  dark  cement 
line  that  sometimes  appears  around  inlays  in  the  front  teeth, 
these  acids  being  the  ones  most  commonly  found  in  fruit  into 
which  the  front  teeth  are  apt  to  be  sunk. 

The  procedure  for  testing  the  solubDity  of  the  cement  films 
was  as  follows:  The  above-mentioned  j-inch  squares  of  etched 
glass  and  etched  agate  were  carefully  cleansed  and  dried.  Then 
finely  ground  Harvard  cement  was  mixed  to  a  creamy  consistence 
and  squeezed  between  the  pieces  of  glass  and  agate  for  about  a 
minute,  and  the  cement  allowed  to  set  for  fifteen  minutes  in 
the  air.  At  the  end  of  that  time  the  edges  of  the  glass  were 
cleansed  of  cement  with  a  lancet  and  the  protected  films  placed 
in  a  bottle  containing  the  solutions  in  which  they  were  to  be 
tested.  They  were  then  placed  in  a  culture  oven  where  blood 
temperature  was  maintained,  and  observations  taken  at  suit- 
able intervals.  The  first  action  of  any  dissolution  of  the  cement 
was  noticed  when  the  remnants  of  the  cement  film  that  adhered 
to  the  face  of  the  etched  agate  after  the  glass  had  been  cemented 
in  place  dissolved,  leaving  the  surface  of  the  agate  absolutely 
clean.  Any  disintegration  of  the  cement  film  between  the  glass 
and  the  agate  was  clearly  visible  through  the  glass.  These 
tests  made  with  sahva  solutions  were  accompanied  by  control 
tests  of  aqueous  solutions  of  the  same  strength. 

The  first  test  to  be  reported  was  made  with  a  protected  film 
in  I  :  1000  solution  of  lactic  acid  and  saliva,  and  i :  looo  aqueous 
solution  of  lactic  acid.  To  the  saliva  were  always  added  a  few 
drops  of  ether  or  chloroform  to  prevent  fermentation.  In  one 
day  there  was  a  perceptible  fine  of  disintegration  about  the 
glass-covered  film  in  the  aqueous  solution,  which  steadily  in- 


332  MODERN  DENTISTRY 

creased.  The  film  in  the  saliva  solution  did  not  show  disintegra- 
tion until  the  third  day.  At  the  end  of  ten  days  the  film  in  the 
aqueous  solution  had  dissolved  0.035  inch  all  around  the  edge. 
It  took  the  saliva  solution  thirty  days  to  accomplish  the  same 
result,  this  test  showing  clearly  that  the  saliva  reduced  the  speed 
of  the  cement  disintegration  to  one-third  of  what  occurred  in 
an  aqueous  solution.  Moreover,  lactic  acid  in  this  solution  made 
a  clean  dissolution  without  causing  the  cement  to  become  rotten 
and  soft.  For  final  observation  the  glasses  were  taken  off  the 
films,  which  were  tightly  adherent  to  the  agate,  and  the  cement 
beneath  was  examined.  In  each  instance  what  remained  was 
found  to  be  hard  and  apparently  unchanged  to  the  cut  of  the 
knife.  The  films  when  measured  were  about  0.0015  inch  in 
thickness,  the  extra  thickness  being  due  to  the  uneven  etching 
of  the  glass  and  agate.  Hereafter  the  ordinary  thin  film  of  cement 
will  be  considered  to  be  about  0.0015  inch  in  thickness. 

Tests  were  next  made  on  cement  films  in  solutions  of  saliva 
and  lactic  acid  that  would  not  cut  enamel.  Cement  films,  as 
above  described,  of  about  0.0015  iiich  in  thickness  were  placed 
in  a  sahva  and  lactic  acid  solution,  i  :  1000,  and  also  in  a  i  :  1000 
aqueous  solution  of  lactic  acid.  It  might  be  interesting  to  note 
here  that  lactic  acid  and  saliva,  i  :  1000  solution,  has  a  decided 
acid  taste.  At  the  end  of  thirty  days  the  film  in  the  aqueous 
solution  of  I  :  1000  lactic  acid  had  dissolved  to  a  distance  of 
0.0625  iiich  from  the  edge  of  the  glass,  while  the  film  in  the 
I  :  1000  lactic  acid  and  saliva  solution  showed  no  signs  of  dis- 
solution at  all.  Covered  films  placed  in  i  :  500  lactic  acid  and 
one  person's  saliva  in  thirty  days  showed  sHght  but  perceptible 
dissolution  around  the  edge  of  the  glass;  while  a  similar  test  made 
with  another  sahva  in  a  corresponding  lactic  acid  solution 
showed  no  perceptible  deterioration  in  the  cement  film.  In  fact, 
one  of  the  cement  films  kept  in  a  i  :  500  lactic  acid  solution  with 
the  latter  sahva  for  six  months  just  began  to  show  signs  of  dete- 
rioration at  the  glass  edge  at  the  end  of  that  time.  Thus,  some 
saHvas  unquestionably  are  better  able  by  far  to  preserve  cement 
and  enamel  against  acids  of  a  certain  strength  than  are  others. 
Numerous  tests  with  acid  solutions  made  from  the  salivas  of 


EXPERIMENTS    CONCERNING   VARIOUS    CEMENTS  333 

various  patients  conclusively  proved  that  salivas  vary  in  their 
relative  power  of  restraining  acid  decalcification  both  of  tooth 
structure  and  cement. 

Another  test  of  interest  was  the  following :  A  covered  cement 
film  had  been  left  in  a  i  :  looo  solution  of  lactic  acid  and  saliva 
for  two  months  in  the  summer,  during  which  time  the  solution 
had  fermented.  The  specimen  was  taken  out  and  found  to  be 
apparently  unharmed.  The  specimen  was  replaced  in  a  fresh 
solution  of  lactic  acid  and  sahva,  i  :  300.  At  the  end  of  twenty- 
four  hours  the  author  was  astonished  to  find  the  cement  film 
dissolved  0.0625  inch  from  the  edge  of  the  glass.  A  further 
immersion  in  the  i  :  300  lactic  acid  and  saliva  solution  made 
only  the  slow  progress  one  would  naturally  expect.  At  the  end 
of  ten  days  the  glass  was  pried  off,  and  the  remaining  cement 
was  very  adherent  and  apparently  unsoftened,  as  shown  by  the 
knife.  This  test  seemed  to  show  that  during  the  summer,  al- 
though the  edge  of  the  cement  film  had  been  rendered  defective, 
the  I  :  1000  lactic  acid  and  sahva  could  not  entirely  dissolve  it, 
and  that  a  solution  of  i  :  300  lactic  acid  and  sahva  later  readily 
dissolved  the  rotten  portion  in  a  few  hours,  while  the  gradual  dis- 
solution of  the  normal  cement  went  on  with  the  ordinary  speed. 

Tests  were  then  made  to  show  the  relative  speed  with  which 
a  thick  and  a  thin  cement  film  would  dissolve  in  a  given  solution. 
Covered  films  0.0015  inch  thick,  as  above  described,  were  used 
for  thin  films  and  a  thickness  of  about  0.004  inch  for  the  thick 
films.  The  thick  films  were  made  by  squeezing  the  cement 
between  agate  and  glass  held  apart  with  several  layers  of  plati- 
num foil,  o.ooi  inch  in  thickness,  folded  together.  The  thin 
film,  0.0015  inch,  dissolved  twice  as  fast  as  the  thick  film.  In 
fact,  during  a  period  of  two  months  the  thin  film  had  dissolved 
0.0625  inch  from  the  edge,  while  the  0.004-inch  film  in  the  same 
time  had  dissolved  0.003  inch.  The  thick  and  thin  films  tried 
in  I  :  1000  lactic  acid  and  sahva  had  not  dissolved  at  all  during 
the  same  time,  not  even  a  little  film  of  exposed  cement  that  had 
not  been  cleaned  from  the  etched  agate.  This  experiment, 
many  times  repeated,  was  a  stumbling-block,  as  up  to  that 
time  a  very  fine  joint  had  been  thought  to  be  a  protection  against 


334  MODERN  DENTISTRY 

disintegration  of  the  cement  around  the  edge  of  an  inlay.  Moss 
fiber  gold  was  cemented  with  great  pressure  between  the  glass 
and  agate  slabs,  and  the  edges  trimmed  clean  and  flush  with  a 
sharp  lancet.  This  was  done  to  get  the  finest  possible  adapta- 
tion and  the  thinnest  film  of  cement,  so  that  just  as  an  inlay 
would  be  kept  from  its  position  by  the  largest  grain  of  cement, 
so  with  the  moss  fiber  gold  the  apposition  might  be  said  to  be 
represented  by  the  smallest  cement  layer  possible,  since  the 
large  grains  of  powder  would  be  bedded  in  soft  gold.  But  these 
tests  only  reaffirmed  the  fact  that  a  thin  layer  of  cement  will 
dissolve  more  rapidly  than  a  thick  layer  under  similar  conditions. 
And  yet  this  phenomenon,  when  we  come  to  think  it  over,  is 
only  natural — the  less  cement  there  is  to  be  dissolved  by  a  solvent, 
the  more  rapidly  it  will  disappear. 

And  so,  after  all  that  has  been  said  and  done,  the  fine  phos- 
phate of  zinc  cement  film  of  an  inlay  is  no  protection  against 
disintegration;  it  only  looks  better,  especially  if  the  margins  of 
the  inlay  tend  to  discolor.  This  explains  why  the  old  Bing  gold 
inlay  lasted  so  well,  consisting  as  it  did  of  a  thin  gold  shell  and  a 
pin  cemented  into  a  cavity,  both  shell  and  cavity  having  been 
filled  with  cement.  Badly  fitting  though  the  edges  were,  the 
author  has  seen  Bing  inlays  last  for  years  and  does  not  remember 
ever  having  been  able  to  pull  one  of  them  out. 

These  tests  lead  to-  the  following  conclusions:  (i)  In  saUva 
solutions  of  acid,  phosphate  of  zinc  cement  ordinarily  dissolves 
more  rapidly  than  enamel.  (2)  Some  saHvas  are  able  to  protect 
the  cement  from  disintegration,  and  some  salivas  are  not.  (3) 
Where  disintegration  occurs  as  the  only  factor,  a  fine  line  of 
cement  will  dissolve  more  rapidly  than  a  coarse  line  of  cement; 
but  where  friction  and  jambing  of  the  carbohydrates  into  a 
coarse  line  occurs  by  mastication,  undoubtedly  the  cement  in  a 
coarse  line  will  disappear  more  rapidly  than  in  a  fine  line. 

While  the  foregoing  experiments  concerning  solubility  have 
not  the  value  that  they  had  at  the  time  they  were  made,  due  to 
the  fortunate  development  of  the  almost  insoluble  silicious 
cements,  they  are  still  valuable  for  what  they  have  shown  con- 
cerning the  protective  action  of  saliva. 


CHAPTER  XII 

STUDY  OF  THE  ROOTS  AND  GUMS  BY  MEANS  OF  THE 

X-RAY 

The  x-ray  is  most  valuable  as  an  aid  to  diagnosis,  but,  as  pre- 
viously stated,  it  is  not  always  to  be  relied  upon  except  as  an 
important  link  in  the  chain  of  evidence  on  which  a  scientific 
diagnosis  should  be  based. 

Many  dentists  are  now  using  x-ray  machines  with  great 
benefit  to  their  dental  knowledge  and  technic.  In  following 
a  root  canal  it  is  often  of  great  advantage  to  stop  in  the  middle 
of  the  operation,  and  leaving  the  broach  in  position,  to  take  an 
x-ray  film  which  will  promptly  show  just  how  far  the  canal  ex- 
tends and  the  distance  yet  to  be  explored  by  the  broach.  How- 
ever, a  word  of  caution  here  may  not  be  out  of  place.  Medicine 
has  had  numerous  x-ray  martyrs  who  died  or  were  hopelessly 
crippled  in  finding  out  the  danger  of  using  x-ray  machines  with- 
out adequate  protection  or  instruction;  and  dentists  in  using  such 
machines  are  not  only  subjecting  themselves  to  a  great  risk,  but 
they  are  also  subjecting  their  patients  to  the  danger  of  burns 
and  permanent  deformity.  This  risk  no  doubt  will  only  be 
eliminated  when  a  number  of  abnormally  sensitive  patients 
have  been  subjected  to  a  too  long  exposure  by  the  inexperienced 
practitioner,  who  does  not  take  the  now  recognized  precau- 
tionary measures  either  for  himself  or  his  patients.  I  do  not 
wish  to  have  it  inferred  that  I  object  in  principle  to  the  dentist 
taking  x-ray  plates.  I  only  mean  to  state  that  a  dentist  who 
takes  x-ray  films  and  plates  should  obtain  his  knowledge  under 
the  supervision  of  an  expert  rather  than  at  the  painful  expense 
of  his  patients.  In  the  early  history  of  anesthesia  deaths 
from  nitrous  oxid  gas  did  not  occur  by  the  wholesale  because 
at  the  approach  of  complete  anesthetization  the  blue  skin  of 
asphyxiation  warned  the  untrained  dentist  that  death  was 
hovering  near,  and  so  he  was  scared  into  a  state  of  proper 
caution;  but  with  the  x-ray  machine  no  such  warning  is  given, 

335 


336  MODERN  DENTISTRY 

and  a  burn  may  be  administered  by  the  inexperienced  operator 
that  may  mar  and  injure  the  unsuspecting  patient  for  life. 

Whenever  it  is  possible  to  have  a  prehminary  study  made  of 
the  mouth  by  a  series  of  x-ray  plates  or  films,  it  should  be  done, 
as  by  this  means  much  valuable  information  concerning  the 
condition  of  the  roots,  alveoH,  and  peridental  membrane  will 
unquestionably  be  obtained;  but  we  should  not  forget  that  the 
x-ray  plates  cannot  tell  the  whole  story,  as  some  of  the  following 
cuts  will  show,  and  conditions  are  pictured  concerning  pulp 
canals  that  appear  sometimes  worse  and  sometimes  better  than 
they  really  are.  Complete  knowledge  can  only  come  through 
the  use  of  three  valuable  factors:  the  quaHty  of  the  x-ray  plate; 
scientific  interpretation  of  the  plate  by  the  practitioner;  and  a 
careful  control  of  the  plate  findings  by  judicious  comparison 
with  the  clinical  symptoms  of  the  patient. 

When  the  diagnosis  has  been  arrived  at  by  means  of  the 
factors  just  mentioned,  every  area  of  infection  should  be  treated 
accordingly.  But  in  interpreting  the  data  it  should  not  be  for- 
gotten that  heretofore  in  dentistry  there  has  been  an  overzealous 
tendency  to  magnify  the  necessity  for  the  complete  filling  of 
root  canals  to  the  exact  tips.  This  has  been  injudiciously  claimed 
to  be  the  only  means  by  which  infection  at  the  tip  could  be  ab- 
solutely avoided.  This  complete  filling  of  the  root  canals,  as 
has  been  shown  in  Chapter  VI,  is  ordinarily  quite  impossible, 
since  there  are  frequently  three  or  even  five  separate  openings 
at  the  ends  of  a  root ;  and  then  the  mere  filling  of  a  root  canal  to 
the  tip  cannot  insure  against  the  progressive  increase  of  infection 
that  may  have  already  started  in  the  bone  outside  of  the  tooth 
before  the  root  canal  was  filled.  The  dentist's  greatest  care 
after  a  prehminary  study  of  the  x-ray  plate  should  be  first  to 
see  that  the  tooth  is  thoroughly  sterilized  before  it  is  filled ;  not 
the  root  canal,  but  the  entire  internal  structure  of  the  tooth; 
second,  to  fill  it  as  thoroughly  as  he  reasonably  can,  with  the 
aid  of  all  the  scientific  data  obtained;  and  third,  to  have  more 
x-ray  plates  taken  six  months  or  a  year  later.  At  that  time  if 
it  is  found  that  the  tips  have  healed  aseptically,  even  though 
the  root  canals  may  not  be  filled  to  the  tip,  they  can  be  safely 
left  to  take  care  of  themselves.    But  if  areas  of  infection  still 


STUDY   or   ROOTS   AND   GUMS   BY   THE  X-RAY  337 

appear,  even  about  the  apices  of  perfectly  filled  roots,  there 
should  be  surgical  interference;  the  tip  should  be  amputated, 
the  infected  bone  curetted,  and  the  wound  packed  with  antiseptic 
gauze  until  complete  heahng  is  obtained. 

Interpretation  of  Plates.— The  following  ^-ray  plates  are 
presented  with  a  full  appreciation  that  they  have  not,  ui  places, 
the  perfect  outUne  and  clear  dehneation  found  in  many  other 
books  on  this  subject.  Many  of  the  pathologic  conditions  shown 
by  the  plates  are  only  obscurely  demonstrated,  but  as  this  is  the 
difficulty  that  ordinarily  confronts  us  in  the  interpretation  of 
r^^-ray  plates,  the  plates  are  presented  without  being  touched  up. 

Case  No.  i  (Fig.  280).  Here  is  a  case  of  an  active  woman, 
aged  forty-five,  who  in  her  youth  had  tuberculosis,  but  recovered 
from  it.  A  careful  examination  of  the  mouth  disclosed  no  pockets 
of  infection  and  only  an  abnormal  red  line  around  the  necks  of 
the  teeth,  and  yet  the  x-my  plates  seem  to  uidicate  that  the 
lime  salts  are  being  absorbed  from  the  bones  around  the  teeth 
in  a  way  characteristic  of  the  beginning  of  infection.  Blood 
taken  from  the  infected  gums  shows  the  presence  of  Streptococcus 
viridans,  hemolytic  streptococcus,  and  Bacillus  influenzse.  The 
patient  also  had  osteophytes  in  the  knee  and  in  the  lumbar 
vertebra,  and  certainly  needed  treatment,  systemic  rather  than 
local,  since  the  local  condition  could  be  readily  controlled  by 
mouth  scrubbing  and  local  cleansing,  as  described  in  Chapter  II. 
Vaccine  treatment  was  given,  the  vaccine  being  made  from  the 
germs  found  in  the  blood  from  the  gums. 

Case  No.  2  (Fig.  281).  The  next  case  is  of  a  woman  aged 
forty-three.  The  films  show  an  apparently  normal  condition 
of  the  tips  and  the  alveolar  process,  with  the  single  exception 
of  the  anterior  root  of  the  left  lower  second  molar,  which  has  a 
spot  of  infection  and  indicates  that  the  root  canals  will  have  to 
be  opened  and  treated  with  Buckley's  mixture;  and  if  this  is  not 
successful  the  root  must  be  excised  from  the  rest  of  the  tooth 
and  extracted.  However,  the  shadow  upon  the  tip  of  the  anterior 
root  is  accentuated  by  the  fact  that  it  lies  in  the  line  of  the  inferior 
dental  canal,  and  therefore  may  not  be  so  seriously  involved 
as  it  appears  to  be.    And  yet  a  careful  study  of  the  bony  structures 


338 


MODERN  DENTISTRY 


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STUDY    OF    ROOTS   AND    GUMS    BY   THE   X-RAY 


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MODERN  DENTISTRY 


generally  indicates  a  lack  of  lime  salts,  and  consequently  a  lowered 
bacterial  resistance  of  the  bone.  Such  a  diagnosis,  however,  can 
only  be  made  when  the  dentist  knows  just  how  long  the  exposures 
were  made  and  what  tubes  were  used. 

Case  No.  3  (Figs.  282-284).  This  case  is  of  a  woman  forty- 
two  years  of  age  who  had  recovered  from  tuberculosis  of  the 
lungs  some  ten  years  previously.  Her  right  knee  was  badly 
infected  and  enlarged  to  twice  its  size,  with  marked  crepitus, 
and  yet  the  x-ray  of  the  knee-joint,  because  the  infection  is  still 


Fig.  282. — Case  3.  Right  knee,  the  bone  of  which  seems  normal  and  yet  the 
knee  was  swollen  to  twice  its  normal  size.  It  lost  its  swelling  and  shortly  returned 
to  normal  condition  when  three  badly  fitting  shell  crowns  were  removed  from  th^ 
two  right  lower  molars  and  second  bicuspid.   (Plate  made  by  Dr.  Willis  F.  Manges.) 

confined  to  the  soft  tissues,  reveals  nothing.  The  radiograph 
study  of  the  mouth  and  also  of  the  knee  are  shown.  The  x-ray 
shows  nothing  abnormal  at  the  tips  of  any  of  the  roots  except 
in  the  case  of  the  right  lower  first  molar.  The  rarefied  bone  in 
the  upper  jaw  was  not  associated  with  pockets;  the  gum  was  in- 
flamed, but  not  to  the  point  of  breaking  down.  The  patient, 
however,  had  not  used  floss-silk  nor  kept  the  back  teeth  free 
from  bacterial  deposits.  Just  before  the  x-ray  plate  was  made 
three  gold  shell  crowns  that  were  collectors  of  foul  infection 
were  removed  from  the  first  and  second  right  lower  molars 


STUDY    OF    ROOTS    AND    GUMS    BY    THE   X-RAY 


341 


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342  MODERN  DENTISTRY 

and  the  lower  right  second  bicuspid.  The  knee  began  at  once 
to  improve.  What  the  author  wishes  to  emphasize  in  this  case 
is  that  serious  external  mouth  infection,  not  discoverable  by 
the  x-rs^y,  obviously  caused  the  serious  knee  inflammation, 
because  when  the  external  infection  was  removed,  the  swelling 
and  inflammation  in  the  knee  began  rapidly  to  subside.  An 
attempt  was  made  to  extract  the  lower  right  first  molar,  and  as  a 
preHminary  precaution  the  tooth  was  cut  into  two  parts  so  that 
the  roots  would  be  separate  from  each  other,  but  it  was  impossible 
to  get  them  all  out  at  the  first  operation  without  causing  exces- 
sive laceration.  The  roots  broke,  leaving  about  one-third  of  each 
root  in  the  jaw  bone.  These  root  tips  were  allowed  to  remain,  and 
were  easily  removed  in  the  course  of  a  month,  when  the  inflam- 
mation had  loosened  them  and  caused  them  to  float  near  the 
surface.     The  excessive  tightness  is  interesting  in  the  light  of 


Fig.  284. — Case  3.     Shape  of  tips  of  roots  due  to  the  exostosis. 

the  area  of  infection  at  the  tips.  The  tips,  when  extracted,  were 
found  to  be  of  the  shape  shown  in  Fig.  284,  which  accounted  for 
the  difficulty  encountered  in  the  extraction.  It  will  be  observed 
that  the  x-ray  plates  gave  some  warning  of  the  exostosis,  but 
did  not  picture  it  completely.  The  enlargement  was  in  the  line 
of  the  x-rays  and  the  consequent  difficulty  of  extraction  was  not 
made  fully  obvious.  The  removal  of  the  tips  at  the  time  of  ex- 
traction would  have  been  attended  with  great  danger  of  frac- 
turing the  jaw,  and  yet  four  weeks  later  the  inflammatory  proc- 
ess made  it  possible  to  easily  remove  the  broken  ends  with  the 
simple  pry  of  an  elevator.  Had  it  not  been  for  the  systemic 
condition  I  am  convinced  that  judicious  canal  treatment  would 
have  been  justified  and  would  probably  have  saved  the  tooth. 
The  point  of  interest  about  the  case  is  that  the  areas  of  decal- 
cification in  the  alveolus,  being  general,  were  not  such  as  to  im- 
peril the  teeth  or  body  if  judicious  cleansing  had  been  maintained; 


STUDY    OF    ROOTS    AND    GUMS    BY   THE   X-RAY 


343 


and  the  only  tooth  that  did  show  a  darkened  area  of  inflammation 
was  so  firmly  lodged  that  it  would  not  come  out  whole.  The  mere 
removal  of  three  infecting  overhanging  crowns  caused  the  acute 
symptoms  in  the  knee  to  abate,  and  an  autogenous  vaccine  was 
used  to  raise  the  germicidal  power  of  the  blood,  thereby  effecting 
a  complete  cure. 

Case  No.  4  (Fig.  285).  The  next  case  is  that  of  a  married 
woman  aged  thirty-six,  whose  three  elder  sisters  had  died  in 
infancy  from  hereditary  syphiHs.  Plates  are  shown  of  the  in- 
fected upper  and  lower  incisors  as  indicating  the  condition 
when  the  patient  was  first  examined.    Mark  the  darkened  areas 


Fig.  285. — Case  4.  Necrotic  areas  at  tips  of  roots  A  and  B  due  probably  to 
hereditary  syphilis.  Pulp  alive  in  upper  central  incisor.  Note  white  line  of  bone 
extending  from  apical  foramen  of  the  upper  central  incisor  to  healthy  bone  beyond. 
(Films  made  by  Dr.  Willis  F.  Manges.) 

of  infection  above  the  superior  left  central  and  lateral  incisors, 
and  below  the  lower  left  lateral  incisor.  The  patient  suffered 
excessively  from  a  burning  sensation  in  the  tip  of  the  tongue 
that  was  reflected  into  the  sublingual  glands  and  the  glands  of 
the  neck.  The  lower  left  incisor,  marked  A,  was  extracted, 
the  bone  drilled  away,  and  the  opening  packed  with  sterilized 
gauze.  All  of  the  black  bone  that  was  not  removed  by  the  prim- 
ary operation  was  removed  with  an  excavator  during  the  sub- 
sequent daily  dressings.  Occasional  applications  of  aromatic 
sulphuric  acid  were  made  which  expedited  the  separation  of  the 
unhealthy  from  the  healthy  tissues.  At  the  end  of  a  week  the 
entire  wound  was  clean,  pink,  and  covered  with  healthy  granu- 


344  MODERN  DENTISTRY 

lations.  It  was  then  allowed  to  fill  up  and  the  wound  closed 
satisfactorily.  Immediately  after  the  cutting  away  of  the  dead 
bone  the  tongue  symptoms  were  greatly  ameliorated.  During  the 
period  of  inflammation  they  again  appeared,  but  finally,  when 
the  wound  entirely  healed,  they  were  greatly  improved,  although 
not  entirely  ehminated.  In  the  meanwhile  the  patient  was  having 
a  course  of  mercurial  treatment  on  account  of  the  hereditary 
sj^hilitic  history.  It  was  next  determined  to  extirpate  the 
infected  area  over  the  left  upper  superior  central  and  lateral 
incisors,  marked  B.  It  will  be  interesting  to  know  that  the  pulp 
in  the  central  incisor  was  alive,  and  the  course  of  the  blood-vessels 
can  be  seen  in  the  plate,  running  through  the  thin  septum  of 
bone  that  had  not  yet  become  broken  down.  Novocain  and 
suprarenin  were  injected  and  the  bone  drill  inserted  through 
the  gum  into  the  infected  region,  which  was  found  to  be  black, 
cavernous,  and  far-spreading  in  various  small  tentacle-like  pro- 
jections. To  have  cut  all  the  black  bone  out  at  the  first  operation 
would  have  meant  the  loss  of  the  teeth  as  far  as  the  first  bicuspid 
on  one  side  and  the  lateral  incisor  on  the  other.  Therefore,  the 
tips  of  the  lateral  and  central  incisors  were  amputated,  the  pulp 
canals  cleansed  and  filled  with  Buckley's  mixture  of  tricresol 
and  formahn,  and  the  wound  packed  with  sterilized  gauze.  The 
next  day  the  dressing  was  removed  and  aromatic  sulphuric 
acid  was  applied  for  three  minutes  on  a  pellet  of  cotton,  and  the 
wound  repacked  with  gauze.  This  was  repeated  on  the  fourth 
day,  and  by  this  time  the  wound  was  spread  open,  the  tips  of 
the  amputated  tips  were  exposed,  and  the  black  remnants  of 
bone  so  softened  and  loosened  that  they  could  be  easily  picked 
out  with  a  spoon  excavator,  leaving  only  living,  sensitive  bone 
and  the  bottom  of  the  wound  clean.  No  such  wound  should 
be  allowed  to  heal  up  while  there  is  any  insensitive  bone  left  at 
the  bottom.  To  do  so  spells  failure  and  probably  a  recurrence 
of  decay.  When  this  had  been  accomplished  the  upper  left 
central  and  lateral  incisors  were  again  opened  and  the  canals 
resterilized.  Gutta-percha  cones  were  then  forced  into  the  canals 
until  they  projected  through  the  foramina,  the  gutta-percha 
trimmed  off  at  the  tips  with  a  hot  instrument,  and  the  teeth 


STUDY   OP   ROOTS   AND   GUMS   BY   THE  X-RA.Y  345 

then  completely  and  permanently  filled  with  cement.  After 
this  the  wound  was  kept  open  with  gauze  until  the  granulations 
filled  up  to  a  point  where  the  wound  was  more  shallow  than 
broad,  care  being  taken  to  see  that  the  bottom  was  entirely 
covered  by  sound,  healthy  tissue.  The  use  of  a  flap  of  gum  and 
the  blod-clot  method,  in  this  instance,  would  have  been  hopelessly 
inefficient.  Bone  operations  about  the  teeth  roots  can  hardly 
ever  be  based  on  the  supposition  of  asepsis.  Such  a  wound 
practically  always  contains  infected  material,  and  drainage  is 
always  necessary.  This  wound  healed  satisfactorily  and  the 
incisors  were  saved. 

Case  No.  5  (Fig.  286).  This  case^  shows  another  illustration 
of  a  darkened  area  of  bone  at  the  tip  of  a  root,  indicating  evident 
infection,  although  the  root  contained  a  Hving  pulp.  The  tooth 
referred  to  is  the  left  upper  bicuspid  supporting  the  bridge.  This 
case  is  that  of  a  woman  suffering  from  secondary  anemia.  Four 
years  previously  she  had  a  hemoglobin  of  30  per  cent,  and  had 
become  so  weakened  that  she  had  lost  the  use  of  her  legs.  She 
was  put  to  bed  for  six  months,  and  under  medical  treatment 
her  hemoglobin  rose  to  75  per  cent.  Since  that  time  she  had 
been  steadily  relapsing,  and  when  the  author  first  saw  her  the 
hemoglobin  of  the  blood  had  again  dropped  to  30  per  cent., 
poikilocytes,  macrocytes,  and  microcytes  being  present.  An 
autogenous  vaccine  was  prepared  from  material  taken  from  a 
pus  pocket  in  the  gum  around  the  tooth  C.  The  left  upper 
second  bicuspid,  marked  A,  was  extracted,  the  anterior  buccal 
root  of  the  right  upper  second  molar,  B,  cut  loose  and  extracted, 
and  the  lower  right  second  molar,  C,  that  showed  an  area  of 
infection  at  the  tips,  also  extracted.  In  three  days  the  poikilo- 
cytes disappeared,  the  red  cells  had  increased  from  3,616,000 
to  3,960,000,  and  the  patient  felt  distinctly  stronger.  The 
vaccine  treatment  was  started,  the  mouth  put  in  hygienic  con- 
dition, and  the  teeth  restored  so  as  to  perform  their  proper  func- 
tions for  accurate  mastication  by  means  of  cleansable  fillings, 
crowns,  and  bridges.  The  great  point  of  interest  in  the  case  Hes 
in  the  fact  that  the  mere  removal  of  the  three  roots  could  have 

1  See  page  106. 


346 


MODERN  DENTISTRY 


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STUDY   OF   ROOTS   AND   GUMS   BY   THE  X-RAY  347 

in  three  days  caused  a  rise  of  seven  points  in  the  hemoglobin  and 
a  disappearance  of  poikilocytes.  At  the  end  of  two  months  the 
patient  returned  to  her  home  in  the  West  and  the  vaccine  treat- 
ment was  continued  there.  In  four  months  after  the  treatment 
was  inaugurated  the  hemoglobin  rose  to  67  per  cent.  After  that 
she  steadily  improved  until  her  health  was  completely  restored. 
Case  No.  6.  The  next  case  is  that  of  a  man  aged  forty-five, 
who  had  been  suffering  from  severe  neuralgic  pains  in  the  right 
side  of  his  head.  The  x-yslj  plate  (Fig.  287)  shows  a  superior 
second  bicuspid  that  had  an  area  of  inflammatory  infiltration 
with  a  projecting  point  of  gutta-percha  at  the  tip.     The  bone 


Fig.  287. — Case  6.  Second  bicuspid  tip  showing  projecting  root  canal  filling 
and  infected  bone  area.  The  tip  was  amputated  and  a  neuralgia  of  two  years' 
standing  at  once  disappeared.     (Film  made  by  Dr.  Willis  F.  Manges.) 

over  the  tip  was  anesthetized  with  novocain,  the  area  drilled 
out,  and  the  tip  of  the  root  smoothed.  This  simple  operation 
alone  caused  his  headaches  to  disappear  permanently.  This  is 
especially  interesting  as  it  shows  how  slight  an  irritation  at  the 
tip  may  cause  a  reflex  action.  And  is  is  especially  of  interest  to 
consider,  if  so  minor  a  spot  of  irritation  happened  to  cause  so 
marked  a  neuralgia,  might  it  not  have  easily  caused  other  types 
of  systemic  disorders  that  were  nevertheless  serious,  although 
their  presence  may  not  have  been  made  manifest  by  the  symp- 
toms of  pain?  This  man  also  had  a  case  of  general  mouth  in- 
fection that  necessitated  treatment  for  over  three  years  before 
it  could  be  controlled.     Figure  288  shows  his  right   shoulder 


348 


MODERN  DENTISTRY 


containing  marked  osteophytes;  and  Fig.   289  is  a  picture  of 
the  same  shoulder  taken  three  years  later,  showing  the  absorp- 


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tion  of  the  osteophytes  so  that  the  joint  is  practically  normal. 
When  this  patient  first  came  under  observation  he  had  contem- 


STUDY   OF   ROOTS   AND    GUMS   BY   THE  X-RAY  349 

plated  an  operation  for  having  the  osteophytes  removed  from 
the  head  of  the  humerus.  The  author  advised  against  it  and  told 
him  to  await  the  effect  of  the  mouth  treatment  and  the  vaccine. 
At  that  time  he  was  having  acute  pains  in  his  shoulder  and  could 
hardly  move  the  arm.  The  treatment  produced  such  beneficial 
results  that  the  patient  decided  against  an  operation.  At  the 
end  of  three  years  the  osteophytes  had  disappeared,  there  was 
no  longer  any  pain,  and  his  arm  had  regained  its  normal  power 
of  movement. 


Fig.  290. — Case  7.     Gutta-percha  projecting  beyond  tip  of  bicuspid  necessitating 
root  excision.     (Plate  made  by  Dr.  Willis  F.  Manges.) 

Case  No.  7.  This  case  shows  a  well-marked  bhnd  abscess 
at  the  tip  of  a  root,  shown  by  the  dark  area  of  inflammation 
at  the  tip  of  the  lower  second  bicuspid  (Fig.  290).  The  gutta- 
percha root  canal  filling  protrudes  through  the  apical  foramen 
into  the  abscessed  region.  The  value  of  the  x-ray  plate  is  here 
made  apparent,  for  this  condition  would  not  have  been  allowed 
to  exist  had  an  :r-ray  plate  been  made  at  the  time  the  root  was 
filled.     Moreover,  the  gutta-percha  would  not  have  protruded 


350 


MODERN  DENTISTRY 


if  the  gutta-percha  point  with  the  oil  of  eucalyptus  had  been  used 
as  described  in  Chapter  VI.  There  were  only  two  possible 
remedies — one  was  to  extract  the  tooth;  the  other  was  to  anesthe- 
tize the  gum  and  bone  over  the  tip  and  amputate  the  lower 
portion  of  the  root,  leaving  the  end  smooth  and  even.  This  latter 
was  done  and  the  tooth  has  been  giving  good  service  ever  since. 
It  will  be  noticed  that  the  infected  region  lies  close  to  the  mental 
foramen.  When  the  operation  of  excision  was  performed  the 
patient  was  warned  that  he  might  lose  sensibility  of  the  lower  lip 
on  that  side.  Immediately  after  the  operation  it  was  found  that 
the   sensibility  was   unimpaired;   but   later   the   inflammation 


Fig.  291. — Case  8.  Posterior  root  excised  of  molar  marked  A.  Crowned 
according  to  Fig.  292.  Molar  marked  B  hopelessly  infected.  Extracted  and 
replaced  by  removable  bridge.     (Films  made  by  Dr.  Willis  F.  Manges.) 


spread  and  the  nerve  trunk  at  the  mental  foramen  became  in- 
volved, and  he  lost  sensibility  in  the  right  side  of  the  lower  lip 
for  three  months.  Since  that  time,  however,  the  normal  sensi- 
bility has  returned  and  the  mouth  is  comfortable. 

Case  No.  8.  This  patient,  a  man  aged  forty-five,  had  two 
lower  molars  that  were  infected  at  the  tips — the  right  lower 
second  molar,  marked  A,  and  the  first  lower  left  molar,  B.  The 
two  cases  would  have  appeared  equally  difficult  to  manage 
without  the  aid  of  the  x-ray  plate.  The  left  lower  first  molar 
roots,  B,  were  extracted,  being  hopelessly  infected,  and  the  molar 
replaced  by  a  removable  bridge.  The  anterior  root  alone  of  the 
right  second  molar  was  extracted,  leaving,  as  the  plate  shows,  a 


STUDY   OF   ROOTS   AND    GUMS   BY   THE  X-RA.Y 


351 


healthy  posterior  root,  A,  on  which  a  satisfactory  crown  was 
constructed  which  entirely  filled  the  space,  and  which  has  been 
doing  good  service  for  over  a  year  and  a  half  (Fig.  292).  It 
was  constructed  as  follows:  The  crown  of  the  anterior  adjacent 
tooth  was  composed  almost  entirely  of  amalgam.  Let  A  repre- 
sent the  anterior  tooth;  B  the  remaining  root  of  the  tooth  from 
which  the  anterior  root  has  been  extracted.  A  platinum  band 
was  fitted  to  the  projecting  portion  of  B.  Porcelain  was  built 
up  on  the  band  to  form  a  crown,  C,  with  a  notch  on  the  side.  Then 
crown,  A,  was  enlarged  by  the  amalgam  addition,  D,  so  that 
it  fitted  into  the  adjacent 
porcelain  crown.  To  make 
the  portion  Z),  the  crown.  A, 
was  well  undercut  and  soft 
amalgam  added  and  dried  of 
its  mercury  by  sponge  gold. 
When  this  was  polished  the 
floss-silk  could  be  passed  be- 
tween the  amalgam  and  the 
porcelain  crown  for  the  daily 
cleansing,  and  yet  the  ledge 
of  amalgam  formed  a  perfect 
support  for  the  porcelain  dur- 
ing the  stress  of  mastica- 
tion. In  this  way  the  tooth 
function  was  as  hygienically 
maintained  as  it  was  prior 
root. 

Case  No.  9  (Fig.  293).  The  x-ray  plate  shows  that  the 
roots  of  the  right  lower  second  molar  were  so  badly  infected  that 
the  tooth  had  to  be  extracted.  The  tips  were  found  to  be  necrotic. 
The  tooth  was  replaced  by  a  removable  bridge.  The  two  upper 
left  bicuspids  were  opened  on  account  of  the  darkened  area  at 
the  root  tips,  and  were  given  a  course  of  sterilization,  filled  with 
gutta-percha  cones  that  were  pushed  into  position  through 
eucalyptus  oil  until  the  tips  wedged.  The  cones  were  then  packed 
thoroughly  into  the  canal  with  warm  instruments.     The  first 


Fig  292. — Case  8.  A,  first  molar 
with  large  amalgam  filling  in  crown; 
B,  posterior  root  of  second  molar,  ante- 
rior root  having  been  excised;  C,  porce- 
ain  crown  with  platinum  shell  for  reten- 
tion; D,  amalgam  addition  to  molar  A 
to  make  a  side  support  for  crown  C. 

to   the   excision  of   the   anterior 


352 


MODERN  DENTISTRY 


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STUDY   OF   ROOTS   AND   GUMS   BY   THE  X-RAY  353 

wedging  of  the  cones  at  the  tips  prevented  any  possibiHty  of  the 
liquid  gutta-percha  being  driven  through  the  apical  foramen. 
The  gums  over  the  darkened  areas  of  the  tips  were  stimulated 
once  a  week  for  several  weeks  by  appHcations  of  the  violet  ray, 
which  greatly  aided  the  restoration  of  the  vitality  of  the  infected 
areas.  The  tip  of  the  right  upper  second  bicuspid  also  was  treated 
in  a  similar  manner,  although  excision  of  the  root  tip  through  the 
alveolus  might  have  been  advisable.  The  impacted  upper  wis- 
dom teeth  were  left  undisturbed,  as  they  were  apparently  causing 
no  reflex  disturbance.  If,  however,  neuralgia  should  develop 
or  even  any  serious,  unexplainable  systemic  symptoms  arise, 
however  far  removed,  the  extraction  of  such  teeth  should  always 
be  held  under  consideration.  The  bones  around  the  lower  in- 
cisors unquestionably  have  lost  a  portion  of  their  Kme  salts,  but 
a  rehef  from  the  irritation  of  the  general  mouth  infection  will 
allow  the  forces  of  recuperation  in  the  bones  to  assert  themselves. 
Case  No.  lo  (Fig.  294).  In  the  next  case  we  have  a  similar 
appearance,  but  more  marked,  of  the  loss  of  the  lime  salts  in 
the  tips  of  the  left  upper  central  incisor  and  left  upper  lateral 
incisor,  in  which  teeth  the  pulps  are  alive  and  without  the  a;-ray 
would  have  been  considered  normal.  The  bone  around  the  tips 
has  started  to  degenerate,  and  unless  it  can  be  stimulated  to 
health,  will  unquestionably  in  time  require  the  bone  drill.  Appli- 
cations of  the  violet  ray  or  electrolysis  in  this  region  wiU  be  val- 
uable; but  if  these  are  not  successful  in  controlling  the  infection 
the  canals  will  have  to  be  opened,  cleaned  out,  and  filled,  in 
spite  of  the  fact  that  the  pulps  in  both  teeth  are  alive  and  show 
no  physical  signs  of  disturbance.  The  right  upper  lateral  in- 
cisor and  left  upper  second  bicuspid  gave  no  evident  clinical 
signs  of  disorder,  and  yet  the  pulps  are  dead  and  the  tips  seem 
unquestionably  absorbed.  The  bony  areas  require  that  the  root 
tips  should  be  excised  and  that  the  adjacent  area  of  lowered 
vitaHty  in  the  bone  should  be  stimulated  to  healthy  growth. 
These  tips  are  only  less  diseased  than  the  left  lower  second  bicus- 
pid and  left  lower  molar,  the  roots  of  which  have  become  hope- 
lessly absorbed.  These  teeth  will  have  to  be  extracted  and  re- 
placed by  a  removable  bridge.  The  bridge  replacing  the  lost 
23 


354 


MODERN    DENTISTRY 


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STUDY    OF    ROOTS   AND    GUMS    BY   THE   X-RA.Y  355 

right  lower  second  bicuspid  has  been  in  position  many  years, 
and  is  doing  excellent  service.  It  is  composed  of  an  inlay  in 
the  molar  to  which  a  gold  cap  for  the  retention  of  a  cemented 
tooth  and  spud  have  been  attached.  It  will  be  noted  that  the 
tips  of  the  second  molar  are  in  good  condition.  The  lack  of  cal- 
cic salts  in  the  alveoli  around  the  lower  incisors  indicates  an 
infection,  and  the  need  of  careful  cleansing  with  fioss-silk  and 
brush  and  a  raising  of  the  bacterial  resistance  with  bacterial 
vaccine. 

Case  No.  ii.  The  next  case  is  that  of  a  man  aged  forty-eight 
years,  who  has  been  under  the  author's  care  twenty-five  years. 
The  work  looks  '^pretty  poor,"  but  a  great  deal  of  it  was  early 
practice  work,  and  since  the  patient  was  perfectly  comfortable 
there  never  seemed  to  be  any  necessity  for  changing  it.  But 
finally,  although  his  mouth  was  still  comfortable,  he  began  to 
show  symptoms  of  toxemia,  the  cause  of  which  his  physician 
was  unable  to  locate.  The  radiograph,  however,  was  most 
enlightening.  All  of  the  bicuspids  except  the  right  lower  first 
bicuspid  were  extracted.  They  are  marked  A,  B,  C,  D,  E,  F,  G 
(Fig.  295).  All  had  tips  denuded  of  peridental  membrane,  and 
cementum  dissolved  and  roughened  with  sharp  points.  The 
first  lower  right  bicuspid,  marked  H,  that  has  a  much  deeper 
shadow  than  the  others,  had  a  Hve  pulp  which  was  removed, 
with  every  chance  that  the  tip  would  recover  under  the  healing 
effects  of  asepsis  and  electrolysis.  In  Fig.  296  B  represents 
the  extracted  root  of  the  left  upper  first  bicuspid,  and  G  the 
extracted  root  of  the  lower  second  bicuspid.  These  are  typical 
of  the  way  all  the  extracted  bicuspids  appeared.  The  anterior 
palatal  root  of  the  left  upper  second  molar  was  excised  and  removed 
by  means  of  the  elevator.  The  right  upper  first  molar  was  opened 
and  a  cotton  dressing  of  years  standing  was  disclosed.  Oh, 
Shade  of  Flagg!  The  dark  areas  over  the  upper  central  incisors 
should  also  be  noted,  merely  to  show  how  much  the  anterior 
palatal  foramen  may  resemble  an  area  of  infection. 

Case  No.  12.  The  plate  (Fig.  297)  shows  three  right  lower 
molars.  The  first  molar,  marked  A,  is  sufficiently  sound  to  be 
treated  externally  with  the  violet  ray  and  the  dry  cell  battery,, 


356 


MODERN  DENTISTRY 


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STUDY   or   ROOTS   AND   GUMS   BY   THE  X-RAY 


357 


Molar  C  also  seems  sound,  but  the  anterior  root  of  molar  B  is 
badly  infected,  as  is  shown  by  the  plate.  This  tooth  was  ex- 
cessively sensitive  to  the  shghtest  touch.  The  anterior  root  of 
molar  B  was  extracted,  leaving  the  posterior  root  in  position. 
Figure  298  is  a  photograph  of  the  extracted  root  with  the  abscess 


Case  II. 


sac  attached.  Being  a  recently  acute  condition,  the  sac  was  still 
in  position,  but  later  on  chronic  suppuration  would  have  set  in, 
and  the  membranous  condition  would  have  been  replaced  by 
a  necrotic  cavity  of  bone. 


Fig.  297. — Case  12.  Anterior 
root  of  B  excised  through  the  crown 
and  extracted  (Fibn  made  by  Dr. 
Willis  F.  Manges.) 


Fig.  2c 


-Case  12.    Extracted  anterior 
root  of  molar  B. 


Case  No.  13.  Figure  299  pictures  an  apparently  similar 
inflammatory  condition  of  the  right  lower  second  molar  root. 
And  yet  the  photograph  of  the  extracted  root  (Fig.  300)  shows 
that  the  conditions  were  more  advanced.  The  abscess  sac  had 
been  completely  absorbed  and  the  cementum  at  the  tip  has  been 
denuded  of  its  membranous  covering.  In  this  case  there  was 
no  pain  or  discomfort  and  the  root  was  extracted  on  the  evidence 
of  the  x-ray  plate. 


3S8 


MODERN  DENTISTRY 


Case  No.  14  (Fig.  301).  The  next  case  is  that  of  a  woman, 
aged  twenty-nine  years,  very  poorly  nourished.  The  fihn  of 
the  lower  incisors  is  missing,  but  the  other  illustrations  will  show 
that  a  marked  destruction  of  bone  and  peridental  membrane 
has  occurred.  Her  teeth  were  loosening  and  spreading  in  all 
directions,  but  a  study  of  the  plates  indicated  that  the  mem- 
branes and  bone  around  the  root  tips  were  still  in  a  healthy 
condition.  The  teeth  were  drawn  into  place  by  twisted  silk. 
Mouth  hygiene  was  inaugurated,  with  applications  of  ammonium 
bifluorid  comp.,  and  last,  but  not  least,  an  autogenous  vaccine 
was  given  once  a  week.  The  patient  made  a  rapid  recovery, 
gained  weight,  her  teeth  became  firm,  and  the  gums  healthy. 


Fig.  2Q9. — Case  13.  First  molar 
infected  at  tip.  Note  photograph  of 
extracted  tooth.  (Film  made  by  Dr. 
WiUis   F.  Manges.) 


Fig.  300. — (Zase  13.  Photograph 
of  extracted  first  molar.  Tip  de- 
nuded of  peridental  membrane  and 
roughened. 


Case  No.  15  (Fig  302).  This  case  is  that  of  an  unmarried 
woman  of  thirty-seven  years.  It  will  be  noted  that  the  left  lower 
first  molar  and  second  bicuspid  and  the  first  lower  right  bicuspid, 
marked  respectively.  A,  B,C,  have  areas  of  infection  at  the  tips. 
Observe  the  photographs  of  the  extracted  teeth  (Fig.  303). 
Their  pulp  canals  had  been  filled  years  previously  with  cotton, 
a  fact  which  the  x-ray  did  not,  of  course,  discover.  The  molar 
root  tips,  A ,  were  found  to  be  necrotic,  without  enlargement  of 
the  cementum.  The  second  bicuspid,  B,  was  denuded  of  its 
peridental  membrane  at  the  tip,  but  otherwise,  with  the  exception 
of  a  slight  exostosis,  was  normal.  The  right  lower  first  bicuspid, 
C,  had  an  exostosis  half-way  down  the  root  to  the  tip  with  a  small 
peridental  sac  at  the  end.    The  exostosis  at  the  tip  of  the  left 


STUDY    OF    ROOTS    AND    GUMS    BY    THE    X-RAY  359 


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MODERN  DENTISTRY 


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STUDY   OF   ROOTS   AND   GUMS   BY   THE   X-RAY  36 1 

lower  first  bicuspid  is  of  interest,  and  the  fact  that  extraction  was 
unnecessary  was  a  source  of  congratulation.  The.  upper  right 
first  molar  had  to  be  extracted  owing  to  absorption  of  the  buccal 
roots  and  infection  at  the  tip  of  the  lingual  root. 

Case  No.  i6  (Fig.  304).  Note  especially  the  right  upper 
lateral  incisor  containing  a  living  pulp  and  the  first  buccal  root 
of  the  left  upper  first  molar  where  the  pulp  had  died.  The  former 
was  extracted  and  the  buccal  root  of  the  latter  was  excised  at 
the  bifurcation.  It  will  be  noted  that  the  other  bony  processes, 
although  absorbed,  are  unusually  retentive  of  their  lime  salts, 
indicating  good  bacterial  resistance  of  the  patient,  which  proved 
to  be  the  case.  The  patient  is  a  vigorous,  active  man  of  fifty, 
and  responded  with  great  readiness  to  the  vaccine  treatment 
after  the  two  infecting  roots  were  extracted  and  careful  mouth 


I 


ABC 

Pig  203. — Case  15.     Extracted  teeth.     Excessive  exostosis  in  B  and  C. 

hygiene  instituted.  In  spite  of  the  loss  of  bone  around  the  lower 
incisors,  they  are  perfectly  firm  under  mastication,  owing  to  the 
healthy  condition  of  the  peridental  membrane  that  yet  remains. 
If,  however,  this  should  get  infected,  the  teeth  will  loosen  and 
be  lost  almost  immediately. 

Case  No.  17  (Fig.  305).  The  next  plate  is  of  a  young  un- 
married woman  of  twenty-seven.  The  patient  showed  marked 
mouth  infection,  especially  of  the  soft  tissues,  associated  with 
great  general  weakness  and  loss  of  vitahty,  a  slight  overtendency 
to  fat,  but  previously  athletic  and  active.  The  two  lower  sixth 
year  molars  are  infected  at  the  root  tips.  These  were  extracted 
and  showed  inflammatory  membranous  sacs  at  the  tips,  smaller, 
but  nevertheless  of  the  same  type  as  the  root  shown  in  Fig.  298, 
Case  No.  12.    But  the  point  of  particular  interest  in  this  case 


362 


MODERN   DENTISTRY 


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STUDY    OF    ROOTS    AND    GUMS    BY    THE   X-RAY 


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364  MODERN  DENTISTRY 

lies  in  the  general  absence  of  lime  salts  in  the  bones,  especially 
around  the  upper  bicuspids  and  the  lower  incisors.  This  indicates 
a  tendency  for  the  breaking  down  of  all  the  tissues.  The  mouth 
was  placed  in  a  satisfactory  hygienic  condition  and  autogenous 
vaccine  given  with  beneficial  results. 

Case  No.  18  (Fig.  306).  This  skiagraph  portrays  the  lower 
central  incisors  showing  an  area  of  decalcification  at  the  tip 
of  the  right  central  incisor.  This  was  supposed  to  be  a  spot 
of  infection,  and  marked  as  such  by  a  prominent  x-rsij  man. 
But  the  tooth  gave  normal  responses  to  heat,  and  a  close  study 
of  the  plate  will  show  that  the  lacunae  are  present  in  the  decalci- 
fied area,  showing  that  the  bone  is  not  broken  down.  A  later 
study  of  the  mouth  is  shown  by  the  larger  plate  (Fig.  307). 


Fig.  306. — Case  18.    Supposed  spot  of  bone  infection  marked  by  arrow. 

The  right  first  lower  bicuspid  contained  a  cotton  root  canal 
dressing  that  had  been  slowly  spreading  infection  in  the  root  under 
the  crown  ever  since  the  crown  was  inserted — a  period  of  some 
five  or  six  years.  The  right  upper  first  bicuspid  that  was  ex- 
tracted shows  a  slight  infection  of  the  buccal  root,  the  Jingual 
root  appearing  normal.  There  is  little  doubt  that  the  root  might 
have  been  saved  if  general  symptoms  of  rheumatism  had  not 
demanded  its  removal.  The  right  lower  second  molar  had  a 
membranous  sac  on  the  tip  with  a  certain  amount  of  absorption 
of  the  alveolar  process  around  it.  The  dark  line  in  between  the 
roots  of  the  left  lower  molar  did  not  indicate  a  breaking  away 
of  the  peridental  membrane  from  the  tooth  or  any  real  pocket 
of  infection.    It  only  shows  a  loss  of  lime  salts  in  the  bony  tissues. 


STUDY   OF   ROOTS   AND    GUMS   BY   THE   X-RAY 


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366  MODERN  DENTISTRY 

Case  No.  19  (Fig.  308).  The  lower  second  bicuspid  shows 
so  apparent  a  spot  of  infection  at  the  tip  that  the  local  dentist 
on  the  evidence  of  the  x-ray  plate  had  drilled  into  the  tooth  only 
to  find  the  pulp  alive  and  apparently  normal.  He  was  conse- 
quently at  a  loss  to  understand  the  defined  darkened  area  and  sent 
the  plate  to  me  for  examination.  To  my  mind  it  was  plainly 
a  case  of  enlarged  mental  foramen.  In  the  x-ray  plate  the  mental 
foramen  is  apt  to  appear  as  a  dark  spot  and  great  care  must  be 


Fig.  308. — Case  19.     Darkened  area  at  tip  of  second  bicuspid  is  not  a  chronic 
abscess — it  is  the  mental  foramen. 

taken  in  differentiating  it  from  a  spot  of  infection  by  clinical 
evidence. 

Case  No.  20  (Fig.  309).  This  case  is  that  of  a  man  of  forty- 
three  years,  of  fairly  good  health,  but  who  for  the  last  four  or 
five  years  has  suffered  from  progressive  nervousness  with  a  tend- 
ency to  get  tired  easily.  His  mouth  had  been  looked  after  by  a 
happy-go-lucky  dentist  who  still  uses  cotton  as  a  pulp  canal 
filling.  The  patient  for  years  has  used  a  tooth-brush  without 
cleansing  his  teeth.  This  case  will  be  discussed  in  detail,  as 
the  study  of  the  extracted  roots  serve  as  a  key  for  solving  the 
condition  of  the  whole  mouth.  The  first  two  teeth  that  will 
be  noted  are  the  lower  second  molar,  A,  and  the  upper  first 
molar,  B.  The  anterior  root  of  the  right  lower  molar  was  excised 
by  cutting  the  crown  in  half,  according  to  the  dotted  line,  from 
the  bifurcation  of  the  roots  up  to  the  grinding  surface.  In 
Fig.  310  ^  represents  the  excised  half  of  the  tooth  which  was 


STUDY    OF    ROOTS    AND    GUMS    BY    THE    X-RAY 


367 


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368  MODERN  DENTISTRY 

found  to  have  two  distinct  roots  with  absorbed  and  necrotic 
tips.  Note  the  type  of  shadow  around  this  tip  in  the  plate 
(Fig.  309).  It  is  extremely  faint  and  the  lines  of  demarcation 
in  the  adjacent  bone  are  most  indistinct.  When  we  examine 
the  bone  next  to  the  normal  root,  which  bone  was  found  to  be 
living,  containing  canahculi,  the  shadow  is  far  greater  than  in 
the  spot  where  bony  absorption  was  complete  and  the  peridental 
membrane  completely  destroyed.  The  bone  at  the  bifurcation 
of  the  two  roots  was  alive  and  healthy  to  the  cut  of  the  bur, 
merely  showing  a  sHght  loss  of  density,  indicating  that  it  had 
begun  to  lose  its  lime  salts,  while  the  same  bone  immediately 
adjacent,  that  has  much  less  of  a  shadow,  had  lost  all  of  its 
lime  salts  and  organic  structure.     The  infected  area  clinically 


A  B 

Fig.  310. — Case  20.  Root  marked  A,  remarkable  as  it  is,  is  a  bifurcated  ante- 
rior root  of  lower  second  molar.  As  can  be  seen,  the  root  tips  were  necrotic  and 
absorbed.  Tip  of  the  extracted  root,  B,  was  almost,  if  not  quite,  normal,  and  yet 
it  appeared  badly  diseased  in  the  plate. 

was  nevertheless  much  in  evidence,  and  yet,  when  studied  by 
the  x-ray,  the  Hne  between  the  healthy  and  unhealthy  bone 
became  so  indistinct  as  to  require  the  closest  observation  for  its 
detection.  The  upper  first  molar  has  a  decided  area  of  calcic 
absorption  around  the  anterior  buccal  root.  The  buccal  root 
was  found  to  be  filled  with  cotton,  while  the  palatal  root  contained 
gutta-percha.  It  was  decided  to  excise  the  anterior  buccal  root 
from  the  rest  of  the  tooth,  both  for  the  sake  of  saving  the  tooth 
and  in  order  that  it  might  be  possible  to  examine  the  extracted 
root  and  adjacent  bone  for  the  purpose  of  determining  the  mean- 
ing of  the  changed  bone  around  the  roots  of  the  upper  bicuspids, 
canines,  and  incisors.  It  will  be  seen  from  the  x-ray  plates  that 
the  bones  around  the  tips  of  the  bicuspids  and  canines  are  appar- 


STUDY   OF   ROOTS   AND   GUMS    BY   THE   X-RAY  369 

ently  more  lacking  in  lime  salts  than  the  bone  around  the  tip 
of  the  buccal  root  that  was  extracted.  There  is  no  absorption 
of  the  tip,  and  a  macroscopic  examination  of  the  root  showed 
that  it  contained  a  moderately  healthy  tip  with  an  adherent 
peridental  membrane  that  was  perhaps  slightly  thickened 
(Fig.  309,  B).  This  fact  convinced  the  author  that  antiseptic 
treatment  and  filling  combined  with  external  electrolysis  might 
have  been  amply  able  to  restore  health  to  the  complete  tooth. 
The  tooth,  A,  was  then  restored  to  normal  occlusion  by  carving 
the  crown  and  building  it  up  to  proper  contour  with  porcelain. 
The  pulp  in  the  right  upper  lateral  incisor  proved  to  be  dead 
and  putrescent,  although  the  bone  at  the  tip  did  not  seem  es- 
pecially unhealthy.  Strangely  enough,  it  gave  a  sharp  thrill 
under  the  application  of  the  cautery,  which  at  first  seemed  to 
indicate  that  the  pulp  was  aHve,  but  later  tests  and  further 
analysis  of  the  plate  convinced  me  that  the  pulp,  even  if  it  were 
alive,  should  be  removed.  I  then  found  on  opening  this  tooth 
that  the  pain  from  the  cautery  application  had  arisen  from  the 
e3q)ansion  of  the  heated  gas  sealed  within  the  canal,  making 
pressure  upon  a  sensitive,  inflamed  apical  foramen.  The  right 
upper  central  incisor  also  had  a  putrescent  pulp,  but  it  gave  no 
response  to  the  application  of  heat.  All  of  the  upper  teeth, 
where  there  were  bony  changes  similar  to  those  that  had  occurred 
in  the  upper  extracted  molar  root,  were  filled,  with  the  full  con- 
viction that  antiseptic  dressings  and  fillings,  combined  with 
external  electrolysis  and  mouth  hygiene,  would  be  amply  able  to 
restore  the  tissues  to  health.  The  case  is  kept  under  observa- 
tion, and  if  a  later  x-ray  plate  shows  that  complete  healing  has 
not  taken  place  amputation  of  the  tips  of  the  roots  will  be  neces- 
sary. 

Case  No.  21  (Fig.  311).  This  represents  the  mouth  of  a 
woman  of  seventy,  well  preserved  and  active.  The  plates  show 
a  general  loss  of  bony  substance  that  at  her  age  might  be  called 
normal,  although  in  a  person  of  thirty  it  would  be  considered 
a  sign  of  some  depressing  systemic  infection.  All  of  the  teeth  are 
firm  with  the  exception  of  the  left  lower  second  molar,  marked  A . 
This  was  quite  loose,  and  a  careful  examination  will  show  the 
24 


37° 


MODERN  DENTISTRY 


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STUDY   OF   ROOTS   AND    GUMS   BY   THE   X-RAY 


371 


faint  area  of  tissue  change  that  was  noticeable  in  the  previous 
case  around  the  lower  molar  root  that  had  to  be  extracted. 
This  tooth  was  extracted  and  the  tips  were  found  rough  and 
denuded  of  peridental  membrane.  The  right  lower  second 
bicuspid,  marked  B,  claimed  attention,  owing  to  the  changed 
bony  area  at  the  tip.  This  area,  it  will  be  noted,  was  much  more 
obvious  than  the  area  around  the  molar  marked  A.  There  is 
exostosis  of  the  root,  and  the  lacunae  of  the  bone  in  the  affected 
area  are  very  indistinct.  The  tooth  was  opened,  disclosing  a 
living  infected  pulp,  which  was  removed  with  the  expectation 
that  the  tooth  and  adjacent  bony  tissue  would  recover  their 


Fig.  312. — Healthy  man,  thirty-five  years  of  age.  Anterior  root  of  ^  excised 
through  the  bifurcation  of  the  root  and  extracted.  It  had  an  abscess  sac  only 
slightly  smaller  than  that  of  Case  12.     (Films  made  by  Dr.  Willis  F.  Manges.) 


normal  tone.  This  was  especially  probable  from  the  fact  that 
the  adjacent  molar,  marked  C,  the  root  canals  of  which  had  been 
filled,  had  healed  so  satisfactorily  about  the  canal  tips.  General 
mouth  hygiene  and  routine  dentistry  caused  the  rest  of  the  mouth 
to  heal  satisfactorily. 

Case  No.  22  (Fig.  312).  This  next  case  is  that  of  a  healthy 
man  of  thirty-five  years  whose  right  lower  molar,  marked  A ,  is 
defective  in  the  anterior  root.  This  was  excised  in  the  usual 
way  from  the  bifurcation  of  the  root  up  through  the  crown  to 
the  grinding  surface.  The  membrane  was  thickened  on  the  end 
of  the  extracted  root  to  form  a  sac  somewhat  less  than  that  in 
Case  12.    The  posterior  root  was  treated  and  filled,  and  later 


372  MODERN  DENTISTRY 

formed  an  excellent  abutment  for  a  bridge.  It  will  be  noticed 
that  the  two  lower  incisors,  marked  C,  have  a  much  more  readily 
observable  area  of  infection  around  their  tips.  Both  of  these 
teeth  were  loose,  although  the  teeth  had  no  external  signs  of 
decay  and  both  pulps  were  ahve.  The  pulps  in  both  were  re- 
moved, the  canals  steriHzed  and  filled,  and  in  about  six  months 
the  teeth  tightened  and  the  mouth  made  a  satisfactory  recovery. 
Case  No.  23  (Fig.  313).  In  this  case  the  two  upper  central 
incisors  had  received  a  blow  during  a  game  of  football.  The 
right  upper  central  incisor  became  sensitive  and  began  to  dis- 
color.   The  pulp  was  removed  and  the  canals  filled.    With  the 


Fig.  313. — Case  23.    Right  upper  central  incisor  given  a  blow  during  a  game  of 
football,  that  caused  the  pulp  to  die.     (Fibns  made  by  Dr.  Willis  F.  Manges.) 

history  and  clinical  facts  at  our  disposal,  the  slight  discoloration 
at  the  tips,  as  shown  by  the  plate,  are  significant,  but  it  must 
not  be  forgotten  that  such  discolorations  are  apt  to  occur  in  this 
region  owing  to  the  presence  of  the  anterior  palatal  foramen, 
and  therefore  it  is  probable  that  the  x-ray  by  itself  would  not 
give  rehable  evidence.  A  soft  tube  will  differentiate  soft  tissues 
more  than  a  hard  tube,  but,  after  aU,  we  must  remember  that  the 
x-iSiy  of  the  mouth  usually  only  gives  information  concerning 
the  hard  tissues,  while  the  inflammation  may  be  largely  confined 
to  the  soft  tissues.  Still  a  careful  examination  of  the  right  upper 
central  will  show  an  interesting  area  of  darkening. 


STUDY   OF   GUMS   AND   ROOTS   BY   THE  X-RA.Y 


373 


2Q 


s  -^ 
-a  g 


11 


S.2 


374  MODERN  DENTISTRY 

Case  No.  24  (Fig.  314)  is  that  of  the  mouth  of  a  young  woman 
of  twenty-five  years  who  has  suffered  intense  neuralgic  pains 
for  over  two  years.  These  pains  were  in  both  jaws,  the  left  ear, 
and  radiated  down  the  left  shoulder  and  arm  to  the  first  and 
second  fingers.  So  desperate  was  her  condition  and  so  obstinate 
her  case  that  it  seemed  a  true  case  of  central  trifacial  neuralgia. 
Her  doctor,  a  diagnostician  of  wide  reputation,  was  unable  to 
find  anything  wrong  with  her  organs  or  general  system.  Her 
ears  were  pronounced  normal  by  a  specialist,  and  finally  she 
was  sent  to  have  an  x-ray  taken  of  her  mouth  and  teeth,  and  the 


Fig.  315. — Case  24.     A  represents  pulp  stone,  actual  size,  taken  from  molar 

marked  A. 


author  was  requested  to  examine  her  mouth  for  possible  sources 
of  trouble.  A  cursory  examination  of  the  x-ray  plates  seemed  to 
show  an  unusually  healthy  condition  of  membranes  and  bone 
around  the  tips  of  all  the  teeth.  But  a  more  careful  examination 
of  the  right  upper  second  molar,  A ,  shows  the  presence  of  a  large 
pulp  stone  within  the  pulp  chamber.  This  tooth  was  excessively 
sensitive  to  the  application  of  heat.  The  pulp  was  anesthetized 
and  removed,  and  Fig.  315  shows  the  photograph,  actual  size, 
of  the  pulp  stone  that  was  removed  from  the  pulp.  It  does  not 
appear  as  large  in  the  x-ray  plate  as  in  the  photograph,  since  it 
was  foreshortened,  lying  in  the  tooth  in  the  line  of  the  ray. 


STUDY    OF    ROOTS    AND    GUMS    BY    THE    X-RAY  375 

The  lower  right  first  molar,  B,  gave  excessive  response  to  the 
application  of  heat,  and  its  pulp  was  removed.  It  contained  a 
large  infiltration  of  calcic  salts.  The  left  upper  canine,  C,  also 
had  a  congested  infected  pulp  that  was  removed.  These  three 
teeth  were  treated  in  one  day,  the  intense  neuralgic  pain  was 
accentuated  for  twenty-four  hours,  and  the  next  day  disappeared 
permanently. 

The  intense  pain  being  removed,  other  teeth  began  to  give 
local  manifestations,  and  the  upper  first  and  second  right  bicus- 
pids revealed  partly  necrotic  and  dead  pulps.  These  were  re- 
moved and  the  teeth  treated.  The  upper  left  second  bicuspid 
was  found  infected  and  inflamed  under  a  cement  filling,  and  the 
upper  right  molar  revealed  an  aching  pulp  from  which  five  small 
pulp  stones  were  removed,  and  the  canals  finally  cleansed  and 
treated. 

This  procedure  caused  almost  complete  alleviation  of  the 
suffering.  The  arm  is  steadily  improving,  and  under  the  vaccine 
treatment,  supplemented  by  obvious  dental  work,  there  is  every 
reason  to  believe  that  her  relief  will  be  permanent.  This  case 
particularly  shows  the  value  as  well  as  the  limitations  of  the 
x-ray. 

It  will  be  noted  that  the  most  serious  conditions  are  by  no 
means  shown  by  obvious  signs,  and  that  the  most  threatening 
changes  may  be  rather  the  beginning  of  infection  than  the  actual 
infection  itself.  And  yet  there  is  the  ink-black  area  associated 
with  hereditary  syphilis  that  certainly  demands  surgical  inter- 
ference. 

In  the  light  of  these  varied  degrees  of  shadow,  the  contra- 
dictory significance  of  the  shadows  and  the  absence  of  shadow, 
we  must  repeat  that  although  the  a;-ray  is  invaluable  as  one  of 
the  means  of  diagnosis,  it  is  not  in  itself  always  conclusive,  and 
should  be  supplemented  by  all  the  clinical  confirmatory  evidence 
possible  if  the  threatening  beginnings  of  infection  are  not  to  be 
overestimated,  and  the  dangerous,  faintly  defined  areas  of  in- 
fection are  not  going  to  be  altogether  overlooked. 


INDEX 


Abrasives   in  dentifrices,  injury  from, 

60 
Abscess,  alveolar,  109 
treatment,  no 
self-perpetuating,  of  mouth  infection 
20 
Abutments,  divergent,  in  bridge  work, 

292 
Acid  calcium  phosphate  solution,  effect 
of,  on  enamel,  44 
sodium  phosphate  solution,  effect  of, 
on  enamel,  44 
Acids,  fruit,  effect  of,  on  enamel,  53 

protective  power  of  saliva  against, 
46 
protective  power  of  saliva  against,  44- 
Active  immunization,  86 
Adhesion  of  cements,  320 
All-gold  and  porcelain  bridge  303 
Alveolar  abscess,  109  , 

treatment,  no 
Amalgam  as  cement,  187 
crown  with  porcelain  facing,  267 
fillings,  186 

method  of  making,  190 
for  attaching  facings,  188 
for  repairing  broken  roots,  1 88 
for  restoration  of  crown,  189 
for  retaining  inlays,  185 
uses  of,  185 
Amboceptor,  87 

Ameba  buccalis  in  mouth  infection,  108 
Ames  cement  slab,  308 
Amputation  of  roots,  x-ray  examination 

before,  137 
Anaphylaxis,  88 
Anchorage,  Baker,  for  orthodontia,  222- 

225 
Anemia  and  vaccine  treatment,  106 
24 


Anesthesia,  local,  infiltration  of  gums  in, 
114 

nerve-blocking  in,  114 

Ringer's  solution  for,  in 

syringe  for,  t  13 
pressure,  117 

disadvantages,  119 
Angle  appliances  for  orthodontia,  223 
Antigen,  87 

Antiseptics  as  mouth-washes,  57 
Arch,  expansion,  Fauchard's,  208 
Attached  bridge,  282 
Author's  method  for  ascertaining  proper 

vaccine  dose,  105 
Autogenous  vaccines,  91 

advantages,  92 

germs  used  for,  96 

Bacilli  used  for  autogenous  vaccines,  96 

for  stock  vaccines,  97 
Bacillus  influenzae,  96 
Baker  anchorage  for  orthodontia,  222- 

225 
Baking  fillings,  1 74 
Band  crown,  272 
Beutelrock  driUs,  122,  123 
Bifluorid   of  ammonium   in   tartar   re- 
moval, 81 
Bleaching  after  removal  of  dental  pulp, 

133 
Blood,  bactericidal  power  of,  in  mouth 
infection,  56 

examination,  in  mouth  infection,  67 
Bone  drills,  143 
Bridge,  attached,  282 

double  clasp,  298 

inlay  cantilever,  285 

porcelain  and  all-gold,  303 

removable,  290 

377 


378  INDEX 

Bridge  work,  attention  to,  in  mouth  in- 
fection, 76 
divergent  abutments  in,  292 
gold  clasps  in,  290 
Broken  roots,  repair  of,  with  amalgam, 

188 
Brush,  tooth-,  proper  selection  of,  28 


Calahan  method  of  treating  root  canals, 

126 
Calcium  phosphate,  acid,  solution,  effect 

of,  on  enamel,  44 
Canals,  root,  Calahan  method  of  treat- 
ing, 126 
emetin  for  treating,  128 
exploring  for,  Flagg's  technic,  131 
filling  of,  1 24 
preparation  of,  122 
steriUzation  of,  1 24 
treatment,  ioq 
variations,  128 
Cantilever  bridge,  inlay,  285 
Cautery,  electric,  in  diagnosis  of  mouth 

infection,  69 
Cement,  adhesion  of,  320 
amalgam  used  for,  187 
as  inlaj'  bond,  327 
experiments  with,  307 
line,  solubility  of ,  3  2  7 

tests  on,  310 
phosphate  of  zinc,  309 
siHcious,  307 

mixing  of,  307 
slab  for  mixing,  308 
Children,  fractured  teeth  in,  treatment, 
204 
orthodontia    in,    for    general    practi- 
tioner, 207 
proper  time  for,  209 
Children's  teeth  and  gums,  care  of,  197 
Citric  acid  in  mouth  infection,  100 
Clasp  bridge,  double,  298 
Cleansing  mouth,  26.     See  also  Month 

cleansing. 
Cocain,  dangers  from,  113 
Color  selection  of  fillings,  170 
Complement,  87 
Crowns,  258 


Crowns,  amalgam,  with  porcelain  facing, 

267 
band,  272 
inlay,  268 
pin,  260 

method  of  making,  263 
restoration  with  amalgam,  189 
setting,  gutta-percha  for,  192 
varieties,  258 
work,  attention  to,  in  mouth  infection, 

75 

Dental  pulp,  109 

indications  for  removal,  no 
removal  of,  120 
bleaching  after,  133 
Dentifrices,  56 

abrasives  in,  injury  from,  60 

destructive  action  of,  60 

magnesium  peroxid,  59,  62 

relation  to  mouth  hygiene,  43 

sodium  perborate,  62 

tests  for  loss  of  tooth  substance  from, 
61 
Dentistry,  operative  efficiency  in,  150 
Dentition,    faulty,    from    malnutrition, 

treatment,  252 
Discoloration  of  teeth,  133 
Divergent  abutments  in  bridge  work,  292 
Double  clasp  bridge,  298 
Drills,  Beutelrock,  122,  123 

bone,  143 

Ear,  infection  of,  relation  to  mouth  in- 
fection, 23 
Electric  cautery  for  diagnosis  of  mouth 
infection,  69 
furnace,  179 
Electrolysis  test  for  mouth  infection,  71 
Emetin  for  treating  root  canals,  128 
in  treatment  of  pyorrhea  alveolaris, 
108 
Enamel,  effect  of  acid  sodium  phosphate 
on,  44 
of  fruit  acids  on,  53 
of  lactic  acid  solution  on,  43 
hardening  of,  43 
softening  of,  43 


INDEX 


379 


Enamel,  study  of,  43 

tests  with  living  saliva,  51-53 
microdynamometer,  46-54 

Excision  of  roots,  142 

Expansion  arch,  Fauchard's,  208 

Exposed   pulp,   treatment   of,   in   tem- 
porary teeth,  203 

Extirpation  of  frenum  of  lip  in  ortho- 
dontia, 239 

Extraction  of  teeth  in  mouth  infection, 
limitations  of,  66 

Eye,  inflammation  of,  relation  to  mouth 
infection,  24 

Fauchard's  expansion  arch,  208 
Filling  of  root  canals,  124 
Fillings,  150 
amalgam,  186 

method  of  making,  190 
baking  of,  1 74 
color  selection  of,  1 70 
for  temporary  teeth,  202 
gutta-percha,  192 
hammered  gold,  151 
making  of,  1 74 
plastic,  184 
porcelain  inlays,  154 
Flagg's   technic  in   exploring   for   root 

canals,  131 
Floss-silk,  functions,  27 
importance  of  use,  27 
method  of  using,  31 
Force  required  in  mastication,  54 

gnathodynamometer  for  measur- 
ing, 55,  56 
Fractured  teeth  in  children,  treatment, 

204 
Frenum  of  lip,  extirpation  of,  in  ortho- 
dontia, 239 
Fruit  acids,  effect  of,  on  enamel,  53 

protective  power  of  saliva  against,  46 
Furnace,  electric,  179 

Gnathodynamometer    for    estimating 

force  in  mastication,  55,  56 
Gold  clasps  in  bridge  work,  290 

fillings,  hammered,  151 

inlays,  179 


Gram-negative  coccobacillus  in  vaccine, 

102 
Gum  infiltration  in  local  anesthesia,  114 

lancing  in  infants,  theory  of,  195 
Gums  of  children,  care  of,  197 

unhealthy,  effect  of  vigorous  brushing 
on,  29 

a;-ray  examination  of,  335 
Gutta-percha  as  cement  for  inlays,  192 

as  filling,  192 

for  setting  crowns,  192 

properties  of,  194 

uses  of,  192 

Hammer,  automatic,   for  diagnosis   of 

mouth  infection,  71 
Hammered  gold  fillings,  151 
Hammond  electric  furnace,  179 
Haptophore,  87 
Hardening  of  enamel,  43 
Hydrogen  peroxid  for  bleaching,  134 
solution  as  mouth-wash,  64 
effects  of,  on  bacteria,  58 

Immunization,  active,  86 

passive,  86 
Impaction  of  teeth,  treatment,  242 
Infants,  gum  lancing  in,  theory  of,  195 
Infected  roots,  excision  of,  109 
Infection,  mouth,  17      See  also  Mouth 

infection . 
Infiltration  of  gums  in  local  anesthesia, 

114 
Inlay  bond,  cement  for,  327 

cantilever  bridge,  285 

crowns,  268 

matrix,  porcelain,  161 
Inlays,  gold,  179 

gutta-percha  as  cement  for,  192 

porcelain,  154 

construction  of,  162 
insertion  of,  176 
cautions  in,  1 76 

retention  of,  with  amalgam,  t8.<; 
Ionization  test  for  mouth  infection,  71 

Lactic  acid  solution,  effect  of,  on  enamel, 
43 


38o 


INDEX 


Lancing  gums    in  infants,   theory  of, 

195 
Lip,  extirpation  of  frenum,  in  ortho- 
dontia, 239 
Local  anesthesia,  infiltration  of  gums  in, 
114 
nerve-blocking  in,  114 
Ringer's  solution  for,  iii 
syringe  for,  113 
Logan-Buckley  scalers,  81 
Lost  teeth,  replacement  of,  282 

Magnesium  peroxid  as  dentifrice,  59,  62 

Making  fillings,  174 

Malnutrition,    faulty    dentition    from, 

treatment,  252 
Mastication,  force  required  in,  54 
Matrix,  porcelain  inlay,  161 
Membrane,  peridental,  tooth  nutrition 

by,  121 
Micrococcus  catarrhalis,  97 
Microdynamometer,  47,  48,  50 

tests  of  enamel,  46-54 
Mouth  cleansing,  26 
dentifrices  for,  56 
floss-silk  in,  31-34 
methods,  26 
mouth- washes  for,  56 
relation  of  dentifrices  to,  43 

of  mouth-washes  to,  43 
tooth-brushing  for,  28,  34-40 
infection,  17 

Ameba  buccalis  in,  108 
attention  to  bridge  work  in,  76 

to  crown  work  in,  75 
bactericidal  power  of  blood  in,  56 
blood  examination  in,  67 
causes,  17 
citric  acid  in,  100 
course  of,  20 
diagnosis,  65 

by  electrolysis,  71 
general,  65 
local,  67 

with  automatic  hammer,  70 
with  electric  cautery,  69 
effects,  17,  23 
electrolysis  test  for,  71 


Mouth  infection,  emetin  in,  108 
examination  of  teeth  in,  68,  76 
genera]  causes,  19 

physical  examination  in,  67 
germs  commonly  obtained  in,  95 
ionization  test  for,  71 
local  causes,  21 
osteoarthritis  in,  vaccine  treatment, 

106 
prevention  of,  26 
relation  of  internal  ear  infection  to, 

23 
of  ocular  disease  to,  24 
of  salivary  gland   infection   to, 

23 

of  spinal  irritation  to,  24 

of  tonsillar  disease  to,  23 
removal  of  foci  in  dental  work,  77 
restoring  normal  occlusion  in,  77 
self-perpetuating  abscess  of,  20 
Streptococcus  viridans  in,  22 
tooth  extraction  in,  limitations  of, 

66 
treatment,  65 

emetin,  108 

local,  75 

of  loose  teeth  in,  78 

of  pus  pockets  in,  100 

specific,  79 

vaccine,  85 

cautions  in,  90 
urine  examination  in,  67 
vaccine  treatment,  85 

cautions  to  observe,  90 
violet-ray  in,  74 

with  tuberculosis,  treatment,  100 
a;-ray  examination  in,  78 
restoring,  proper    approximation   in, 

77 
Mouth-washes,  56 
antiseptic,  57 

peroxid  of  hydrogen  solution,  40,  64 
relation  of,  to  mouth  hygiene,  43 
sodium  silicofluorid  solution,  40,  64 

Necrotic  roots,  excision  of,  109 
Nerve-blocking  in  local  anesthesia,  114 
Novocain,  advantage  of  non-toxicity,  1 13 


INDEX 


381 


Novocain-suprarenin  solution  for  local 
anesthesia,  no 

Nutrition,  tooth,  by  peridental  mem- 
brane, 121 

Orthodontia,    Angle    appliances    for, 
223 
Baker  anchorage  for,  222-225 
extirpation  of  frenum  of  lip  in,  239 
in  children  for  general  practitioner, 
207 
proper  time  for,  209 
Osteoarthritis,  mouth  infection  in,  vac- 
cine treatment,  106 
Oxalic  acid  for  bleaching,  134 

Parent  germs,  obtaining  of,  for  vac- 
cines, 93 
Passive  immunization,  86 
Perborate  of  sodium  as  dentifrice,  62 
Peridental   membrane,   tooth   nutrition 

by,  121 
Peroxid  of  hydrogen  for  bleaching,  134 
solution  as  mouth-wash,  40,  64 
effect  of,  on  bacteria,  58 
of  magnesium  as  dentifrice,  59,  62 
Phosphate  of  zinc  cements,  309 
Pin  crown,  260 

method  of  making,  263 
Plastic  fillings,  184 
Pneumococcus  capsulatus,  98 
Porcelain  and  all-gold  bridge,  303 
inlay  matrix,  161 
inlays,  154 

construction  of,  162 
insertion  of,  176 
cautions  in,  176 
strength  of,  155 
tests  for,  157 
Pressure  anesthesia,  117 
disadvantages,  119 
Pulp,  dental,  109 
functions  of,  76 
removal  of,  120 
bleaching  after,  133 
indications  for,  no 
exposed,  treatment  of,  in  temporary 
teeth,  203 


Pus  pockets,  treatment  of,  in  mouth  in- 
fection, 100 

Pyorrhea  alveolaris,  emetin  treatment, 
108 

Removable  bridge,  290 

Ringer's  solution  for  local  anesthesia, 

III 
Roentgen  ray.    See  X-ray. 
Root  canals,  Calahan  method  of  treating, 
126 
emetin  for  treating,  1 28 
exploring  for,  Flagg's  technic,  131 
filling  of,  124 
preparation  of,  122 
steriUzation  of,  1 24 
treatment,  109 
variation,  128 
Roots,  amputation  of,  ar-ray  examination 
before,  137 
broken,  repair  of,  with  amalgam,  188 
excision  of,  142 

infected  or  necrotic,  excision  of,  109 
x-ray  examination  of,  335 

Saliva,  living,  enamel  tests  with,  51 
protective  power  of,  against  acids,  44 

fruit  acids,  46 
study  of,  43 

Salivary  gland  infection,  relation  of,  to 
mouth  infection,  23 

Scalers,  tartar,  80,  81,  82 

Self-perpetuating  abscess  of  mouth  in- 
fection, 20 

Sensitization,  89 

Sensitized  vaccines,  98 

Silicious  cements,  307 
mixing  of,  307 

Slab  for  mixing  cement,  308 

Smith  scalers,  82 

Sodium  perborate  as  dentifrice,  62 
phosphate,  acid,  solution,  effect  of,  on 

enamel,  44 
silicofluorid  solution  as  mouth-wash, 
40,  64 

Softening  of  enamel,  44 

Solubility  of  cement  line,  327 

Solvent,  tartar,  80 


382 


INDEX 


Spine,  irritation  of,  relation  to  mouth 

infection,  24 
Sterilization  of  root  canals,  124 
Stock  vaccines,  91 
advantages,  92 
germs  used  for,  96 
Streptococcus  pyogenes,  95 

viridans  in  mouth  infection,  22 
Syringe  for  local  anesthesia,  113 

Tartar,  removal  of,  in  mouth  infection, 

79 

with  bifluorid  of  ammonium  in,  81 
scalers,  80,  81,  82 
solvent,  80 
Teeth,  cleaning  of,  26.    See  also  Moidh 

cleansing. 
examination  of,  in  mouth  infection, 

68,  76 
fractured,  in  children,  treatment,  204 
gums,  x-x3t.y  examination,  335 
impaction  of,  treatment,  242 
loose,  treatment  of,  in  mouth  infection, 

78 
lost,  replacement  of,  282 
of  children,  care  of,  195 
roots,  x-xdiY  examination,  335 
temporary,  fillings  for,  202 

treatment  of  exposed  pulp  in,  203 
Test,  electrolysis,  for  mouth  infection, 

71 

for  loss  of  tooth  substance  from  denti- 
frices, 61 

ionization,  for  mouth  infection,  71 

of  enamel  with  living  saliva,  51-53 

with  microdynamometer,  46-54 

Tonsils,  disease  of,  relation  to  mouth 

infection,  23 
Tooth  discoloration,  133 

enamel.    See  Enamel. 

extraction  in  mouth  infection,  limita- 
tions of,  66 

nutrition    by    peridental    membrane, 
121 

pulp,  functions,  76 


Tooth  substance,  tests  for  loss  of,  from 
dentifrices,  61 

Tooth-brush,  proper,  selection  of,  28 

Tooth-brushing,  28 

effect  of,  on  unhealthy  gums,  29 
proper  method,  34-40 

Toxophore,  87 

Tubercle  bacilli  in  vaccines,  102 

Tuberculosis  complicating  mouth  infec- 
tion, treatment,  100 

Urine  examination  in  mouth  infection, 
67 

Vaccination,  theory  of,  85 
Vaccine  treatment  of  mouth  infection,  85 
cautions  to  observe,  90 
with  osteoarthritis,  106 
Vaccines,  autogenous,  91 
advantages,  92 
germs  used  for,  96 
dosage,  100 

author's  method   for   ascertaining, 

105 
Gram-negative  coccobacillus  in,  102 
in  anemia,  106 

obtaining  parent  germs  for,  93 
preparation  of,  90 
sensitized,  98 
stock,  91 

advantages,  92 

germs  used  for,  97 
symptoms  of  reaction  in,  loi 
tubercle  bacillus  in,  102 
Violet-ray  in  mouth  infection,  74 

X-RAY  examination  in  mouth  infection, 
78 
of  gums  and  roots,  335 
of  roots  before  amputation,  13  7 
plates,  interpretation  of,  337 

YuNGER  scalers,  80 

Zinc  phosphate  cements,  309 


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